Psoriasis

What is Psoriasis?

Psoriasis is a chronic dermatological condition characterized by pruritic erythematous patches and silvery scales, with symptom severity varying from mild to severe.

In normal skin, the cells are normally replaced every three to four weeks; however, in individuals with psoriasis, this process is accelerated, occurring within approximately three to seven days. Consequently, this rapid proliferation of skin cells leads to a buildup of skin layers and the manifestation of various symptoms associated with psoriasis.

 

Risk factors of Psoriasis

Risk factors for developing psoriasis include:

  • Family History
  • Infections: Viral infections (like HIV) and bacterial infections (such as strep throat) can trigger psoriasis
  • Psychological Stress
  • Obesity
  • Smoking

 

Causes of Psoriasis

The etiology of psoriasis is not yet fully understood but involves a combination of genetic, immune, and environmental factors Key triggers can include:

  • Skin trauma
  • Psychological stress
  • Infections, notably streptococcal throat infections
  • Smoking 
  • Certain medications

 

Clinical features of Psoriasis

The disease typically follows a relapsing course characterized by intervals of symptom-free periods. It is characterized by well-defined erythematous plaques and/or papules with silver-white scaling. Initial presentations often consist of solitary lesions, which may subsequently merge to form larger confluent areas. These lesions predominantly occur on the scalp, trunk, elbows, and knees—typically the extensor surfaces—though any area of the skin may be involved. Pruritus is reported in approximately 80% of cases, generally mild but occasionally severe.

Characteristic features include:

Auspitz sign, which refers to pinpoint bleeding that occurs upon the removal of scales, revealing dermal papillae.

Additionally, the Koebner phenomenon describes the occurrence of psoriatic lesions on previously unaffected skin in response to physical stimuli or skin injury, such as trauma, scratching, or the friction of irritating clothing, reflecting an isomorphic response. Nail involvement occurs in approximately 50% of cases.

Common manifestations include:

  • Nail pitting: characterized by small, round depressions on the nail surface.
  • Brittle nails: which exhibit dystrophy and crumbling.
  • Onycholysis: defined as partial separation of the nail plate, predominantly at the distal edge.
  • Oil drop sign (or salmon spot): presents as a well-circumscribed yellow-red discoloration of the nail.

 

Types of Psoriasis

  •  Plaque Psoriasis: This is the most prevalent variant, characterized by symmetrically distributed, thick erythematous lesions covered with silvery scales.
  •  Guttate Psoriasis: This variant features lesions resembling the size of drops of water and may progress to plaque psoriasis. It primarily occurs in children and adolescents, often following a streptococcal infection.
  •  Erythrodermic Psoriasis: This form presents as generalized erythematous lesions accompanied by diffuse scaling. It has the potential to lead to severe health complications, including fever and dehydration.
  • Inverse Psoriasis: This variant predominantly affects skin folds and the flexural creases of large joints, commonly referred to as flexural psoriasis.
  •  Pustular Psoriasis: There is a significant association with HLA-B27, with generalized pustular psoriasis being the most common subtype. This variant is characterized by generalized erythroderma and the presence of confluent white pustules over the entire body, potentially involving the oral mucosa and tongue. It typically exhibits a relapsing course, accompanied by pronounced malaise, including fever, weakness, and chills, and can be life-threatening.

 

Health conditions associated with psoriasis

  • Psoriatic Arthritis
  • Spondyloarthropathy
  • Inflammatory Bowel Disease: Includes Crohn’s disease and ulcerative colitis.
  • Uveitis
  • Coeliac Disease
  • Localised palmoplantar pustulosis, generalised pustulosis, and acute generalised exanthematous pustulosis
  • Non-Alcoholic Fatty Liver Disease
  • Metabolic Syndrome

 

Diagnosis of Psoriasis

Psoriasis is a clinical diagnosis based on the patient’s medical and familial history, along with a detailed examination of the skin. Skin biopsy is indicated primarily in cases where the clinical presentation is atypical.

Supporting histological findings include:

  • Acanthosis and parakeratosis
  • Thickening of the stratum spinosum with thinning of the stratum granulosum
  • Presence of Munro microabscesses, which are characterized by the accumulation of neutrophils within the stratum corneum, surrounded by parakeratosis.

 

Treatment of Psoriasis

Psoriasis currently has no cure; however, symptoms can be effectively managed through various medications tailored to the type, severity, and location of the lesions.

1- Topical therapies:

Mild psoriasis is typically managed with topical agents. Common treatments include:

  • Emollients and moisturizers
  • Coal tar preparations
  • Dithranol treatments
  • Salicylic acid
  • Vitamin D derivatives (such as calcipotriol)
  • Topical steroids
  • Combination ointment/gel or foam of calcipotriol and betamethasone dipropionate
  • Calcineurin inhibitors (like tacrolimus and pimecrolimus)

2- Phototherapy

3- Systemic therapies:

For moderate to severe psoriasis, treatment typically involves systemic agents and/or phototherapy. The most commonly used systemic treatments include:

  • Methotrexate
  • Ciclosporin
  • Acitretin

Additionally, other medications that are sometimes used for psoriasis are:

  •  Apremilast
  • Hydroxyurea
  • Dimethyl fumarate

4- Biologic therapies: 

Biologic therapy is specifically used for severe cases of psoriasis and psoriatic arthritis that do not respond to standard systemic treatments.

 

 

Written by:

Atheer Alhuthaili, Medical Intern.

Revised by: 

 Naif Alshehri, Medical Intern

References:

DermNet.

Amboss 

Medscape 

MOH

Epidermolysis bullosa

Definition: 

Epidermolysis bullosa (EB) is defined by mechanical fragility of the skin, it is a group of genetically inherited disorders characterized by the formation of blisters on the skin and mucous membranes, often triggered by minimal trauma or friction, particularly on areas like the hands and feet, in severe cases, blistering can also affect internal organs such as the esophagus, stomach, and respiratory tract, even in the absence of external friction. 

It is classified into four major subtypes: EB simplex, junctional EB, dystrophic EB, and Kindler EB, each distinguished by the specific layer of tissue where blistering occurs. Collectively, these subtypes encompass over 30 distinct clinical phenotypes.

 

Epidemiology: 

According to data from the National EB Registry, the estimated prevalence of epidermolysis bullosa (EB) in the U.S. is 11.1 cases per 1 million people, with an incidence of 19.6 per 1 million live births. 

The prevalence and incidence for major EB subtypes are as follows: EB simplex (6.0 and 7.9), junctional EB (0.5 and 2.7), dominant dystrophic EB (1.5 and 2.1), and recessive dystrophic EB (1.4 and 3.0) per 1 million population and live births, respectively.

 

Etiology: 

EB results from genetic mutations in proteins essential for skin adhesion. These mutations determine where blistering occurs. For example:

  • Epidermolysis Bullosa Simplex: Mutations disrupt proteins within the epidermis
  • Junctional Epidermolysis Bullosa: Mutations affect the dermal-epidermal junction
  • Dystrophic Epidermolysis Bullosa: Mutations impair structures in the upper dermis

The structural weakness in these layers leads to blister formation even with minor friction or trauma.

 

Clinical Features:

Clinically, EB manifests as fragile skin prone to blistering and erosions. 

  • Fragile Skin and Blisters: Skin easily blisters and erodes, especially in areas prone to friction. Scarring is minimal in localized EBS but severe in recessive DEB.
  • Nail and Hair Abnormalities: Dystrophic or missing nails are common, along with scarring alopecia.
  • Extracutaneous Involvement:
  • Eye: Repeated eye blistering may cause neovascularization and blindness.
  • Gastrointestinal: Esophageal strictures, malabsorption, and constipation can develop.
  • Genitourinary: Blistering may result in urethral or bladder strictures.
  • Rare Presentations: Some forms of JEB and EBS may present with pyloric atresia at birth.

 

Approach to Diagnosis of Epidermolysis Bullosa (EB):

Diagnosing EB requires a combination of clinical evaluation and specialized testing. In cases with a known family history, a dermatologist can often make a preliminary diagnosis based on the patient’s symptoms. However, more precise diagnostic tools are often necessary. Skin biopsy with immunofluorescence antigen mapping (IFM) is used to examine newly formed blisters, identifying the defective skin proteins involved. Transmission electron microscopy (TEM) can reveal the ultrastructural level where blistering occurs, although this technique is typically available only in specialized laboratories. With the advancements in genetic testing, next-generation sequencing has become a valuable tool for confirming the diagnosis, pinpointing the exact mutation, and providing genetic counseling for families.

 

Management: 

Currently, there is no cure for EB, and treatment focuses on symptom relief, skin protection, and preventing complications. Key management strategies include:

 Daily Care:

  • Prevent Friction: Use soft clothing, padding, and non-irritating footwear. Handle infants and children with care to prevent skin damage.
  • Maintain a Cool Environment: Avoid overheating, which can trigger blistering.
  • Blister Care: Blisters should be drained and dressed by trained professionals using non-adhesive or silicone-based dressings.

  Wound Management:

  • Bathing Solutions: Sodium hypochlorite or acetic acid baths help prevent bacterial infections.
  • Wound Dressings: Use low-tack silicone dressings or Vaseline®-impregnated gauze to promote healing and prevent trauma during dressing changes.

 Medications:

  • Topical Treatments: Diacerein cream for EBS, and aluminum chloride for managing hyperhidrosis.
  • Systemic Treatments: Antibiotics for infections and drugs like tetracycline or erythromycin for EBS. Emerging therapies, such as retinoids and losartan, aim to reduce severe complications in DEB.
  • Innovative Therapies in Research: Therapies such as Gene Therapy and Stem Cell Therapy are being explored to repair defective genes and improve skin integrity.
  • Specialized Care:Multidisciplinary care teams address complications affecting the esophagus, eyes, and gastrointestinal system.

 

Written by: 

Raneem Alahmadi, Medical Intern.

Revised by: 

 Naif Alshehri, Medical Intern

Resources:

Bolognia 5th edition

Dermnet

Dermatomyositis

Definition:

dermatomyositis is an autoimmune condition that often affects both the skin and the muscles (classic dermatomyositis), but it can alternatively manifest as skin-predominant illness (clinically amyopathic dermatomyositis). While children have no elevated risk of cancer, all adult patients presenting with cutaneous lesions of dermatomyositis should be investigated for concurrent muscle illness, systemic involvement, and/or malignancy.

 

Epidemiology:

Dermatomyositis exhibits a bimodal age distribution, affecting both adults ( 40-60 years) and children ( 4-14 years). It is a rare condition found worldwide. In adults, women are two to three times more likely to develop dermatomyositis than men. The disease occurs at a rate of 2 to 9 cases per million across different populations.

 

Etiology:

Dermatomyositis is thought to arise from an immune-mediated process triggered by external factors, such as malignancy, medications, or infections, in individuals with a genetic predisposition. Serum antinuclear autoantibodies are frequently detected, along with other myositis-specific autoantibodies. Antisynthetase antibodies target cytoplasmic antigens, meaning the antinuclear antibody test may sometimes be negative. Patients with antisynthetase antibodies often present with overlap syndromes. The term “antisynthetase syndrome” is used to describe individuals with these autoantibodies who exhibit symptoms like fever, erosive polyarthritis, “mechanic’s hands,” Raynaud’s phenomenon, and interstitial lung disease.

 

Clinical features:

Cutaneous manifestations:

  • The hallmark features of dermatomyositis include the heliotrope sign and Gottron papules. The heliotrope sign is identified by a pink-violet discoloration, mainly affecting the eyelids and periorbital skin, often accompanied by swelling. Dermatomyositis skin lesions are typically more prominent on extensor surfaces, such as the elbows, knees, metacarpophalangeal joints , and both proximal and distal interphalangeal joints (knuckles). When the papules on the knuckles develop a lichenoid texture, they are referred to as Gottron papules, while involvement of the elbows or knees is called Gottron sign.
  • A key diagnostic feature of the dermatomyositis skin eruption is poikiloderma, which appears as a pink-violet color in dermatomyositis and a more reddish tone in lupus erythematosus. Photodistributed poikiloderma is highly characteristic of dermatomyositis, often seen on the upper chest (V-neck sign) and upper back (shawl sign). It can also occur in areas not exposed to sunlight, such as the lateral thigh, known as the holster sign. The skin lesions of dermatomyositis are frequently very itchy, which can significantly impact the patient’s quality of life. This itching can sometimes help distinguish dermatomyositis from lupus erythematosus.
  • Calcinosis cutis is more common in juvenile dermatomyositis, affecting 25–70% of children. It appears as hard, irregular papules or nodules that may drain a chalky substance. These lesions tend to develop in areas of trauma, like the elbows and knees, but can occur elsewhere and may be painful, potentially interfering with function.

Systemic disease:

In dermatomyositis, skin symptoms often appear before noticeable muscle involvement; however, when muscle disease occurs, it is clinically similar to polymyositis. The myopathy primarily affects proximal muscles, particularly the extensor groups like the triceps and quadriceps, in a symmetrical pattern. In more severe cases, all muscle groups can be impacted. Patients may struggle with simple activities, such as combing their hair or standing up from a seated position. 

Pulmonary complications occur in about 15–30% of dermatomyositis patients and typically present as diffuse interstitial fibrosis, resembling that found in individuals with rheumatoid arthritis or systemic sclerosis. Cardiac involvement is usually asymptomatic, but when it occurs, it typically manifests as arrhythmias or conduction abnormalities.

 

Diagnosis: 

  • A thorough history, including possible triggers and any past malignancies, along with a review of systems, should be conducted.
  • Physical examination – This should include an assessment of the skin, muscles, and a complete general examination.

If the patient presents with a characteristic skin eruption, a skin biopsy is recommended to confirm the clinical diagnosis of dermatomyositis. Once histopathological confirmation is obtained, an evaluation for muscle and/or systemic disease should follow, as this will guide treatment decisions. 

The assessment for myositis may involve testing the strength of proximal extensor muscles and other muscles, including the neck flexors, measuring serum muscle enzyme levels, performing an electromyogram, and/or conducting a triceps muscle biopsy. However, MRI or ultrasound of the proximal muscles is increasingly used instead of, or before, a muscle biopsy, especially when classic skin findings and consistent histology are present. 

Additional baseline tests should be carried out to check for pulmonary, cardiac, or symptomatic esophageal diseases.

 

Management:

Skin-limited disease:

  • First-line treatment: Photoprotection, topical corticosteroids (CS), and calcineurin inhibitors with or without antimalarials.
  • Second-line treatment: High-dose methotrexate (MTX), mycophenolate mofetil (MMF), intravenous immunoglobulin (IVIG), cyclosporine, and rituximab, particularly for severe skin conditions with ulceration.
  • Calcinosis cutis treatment: Diltiazem and possibly surgical removal; early aggressive treatment of juvenile dermatomyositis (JDM) to lower the risk of developing calcinosis cutis.

Disease monitoring:

    • Muscle enzymes and clinical examinations should be rechecked every 2-3 months. If muscle disease develops, systemic steroids should be initiated.
    • Physical exams every 4-6 months to screen for malignancy, especially during the first 2-3 years following diagnosis.

Skin and muscle disease:

  • First-line treatment: Systemic corticosteroids (CS), methotrexate (MTX), and azathioprine (AZA).
  • Second-line treatment: IVIG, mycophenolate mofetil (MMF), cyclosporine, cyclophosphamide, and rituximab.

 

Written by:

Mashael Alanazi, Medical Intern

Revised by: 

Naif Alshehri, Medical Intern

Resources:

Bolognia textbook

Review of dermatology textbook

Systemic Sclerosis

What is Systemic Sclerosis?

Systemic Sclerosis (SSc) is an autoimmune inflammatory disorder that can cause extensive fibrosis and vascular abnormalities, affecting various organs such as the skin, lungs, gastrointestinal tract, heart, and kidneys. 

Systemic sclerosis is classified into subtypes based on the pattern of skin involvement:

  • Diffuse Cutaneous Systemic Sclerosis (dcSSc)
  • Limited Cutaneous Systemic Sclerosis (lcSSc)
  • Systemic sclerosis sine scleroderma

 

Causes of Systemic Sclerosis 

The exact cause of systemic sclerosis remains unclear, but it is believed to result from a combination of genetic, environmental, and immunological factors:                                                                                                 

  •  Genetic Factors: Specific genetic loci that are associated with the disease have been identified.                                                                                  
  •  Environmental Triggers: Exposure to certain environmental factors, such as silica dust, vinyl chloride, trichloroethylene, and some drugs (e.g., penicillamine), may trigger the disease in genetically predisposed individuals.                                                                                                                                                                            
  • Immune pathways: Several pathways are likely implicated in the development of systemic sclerosis. These include cytokines that damage blood vessels, growth factors that promote collagen production, integrin signaling, morphogen pathways, co-stimulatory pathways, and others.

 

 

Clinical features of Systemic Sclerosis 

Generally there is thickening and hardening of the skin, which appears smooth, shiny, and puffy.

Hands

  • Sclerodactyly
  • Puffy Fingers
  • Raynaud’s Phenomenon: Reduced blood flow to fingers in response to cold or stress.
  • Nail Changes: abnormal capillaries at the nail fold, smaller fragile nails with ragged cuticles, and digital pitted scars.
  • Digital Ulcers
  • Palmar erythema affecting thenar/hypothenar eminence

Face

  • Matt Telangiectases
  • Peri-Oral Furrowing 
  • Microstomia
  • Beaked Nose

Other Features

  • Calcinosis: Deposits affecting fingers and extensor surfaces, which can break down and discharge chalky material (calcium)
  • Salt and Pepper Dyspigmentation:  of hyperpigmentation and vitiligo-like depigmentation.
  • Pruritus

Rarer Cutaneous Features

  • Morphoea: Often appears as plaque, nodular, or linear lesions; more common in limited cutaneous systemic sclerosis.
  • Panniculitis

Organ Involvement: 

  • It can affect the lungs, heart, kidneys, and gastrointestinal tract.
  • Constitutional symptoms are common, such as fatigue, arthralgia, and myalgia.

 

Diagnosis of Systemic Sclerosis 

Diagnosing systemic sclerosis (SSc) involves a combination of clinical evaluation, laboratory tests, and imaging studies.

Key Features for Diagnosis

  • Sclerodactyly
  • Abnormal Nail Fold Capillaries are detected through capillaroscopy or dermatoscopy.
  • Autoantibodies: Testing for specific autoantibodies:
  • Anti-Scl70
  • Anticentromere antibodies
  • Internal Organ Involvement: Evidence of fibrosis or damage in internal organs, such as the lungs, heart, or kidneys.

Laboratory Tests

  • Antinuclear Antibodies (ANA): Often positive in SSc patients.
  • Inflammatory Markers: CRP and ESR 
  • BNP

Additional Investigations

  • Pulmonary Function Tests
  • High-Resolution CT (HRCT) Chest
  • Echocardiogram
  • Gastrointestinal Studies: Such as EGD to assess esophageal involvement
  • In some cases, a skin biopsy may be performed

 

Treatment of Systemic Sclerosis 

There is no cure for systemic sclerosis, treatment is mainly symptomatic and organ system specific.

Supportive care

  • Protect hands from trauma and cold exposure (e.g., by wearing gloves)
  • Keep skin moisturized (e.g., with warm oil, paraffin baths, and emollients)
  • Promote smoking cessation
  • Consider vasodilatory physical therapy and lymphatic drainage
  • Provide antihistamines for pruritus

Cutaneous Disease Management:

Raynaud Phenomenon (RP): First-line treatment includes calcium channel blockers.

For severe or refractory cases, consider adding oral PDE-5 inhibitors (e.g., sildenafil) or IV iloprost.

Digital Ulceration (DU):  PDE-5 inhibitors (e.g., tadalafil) or IV iloprost.

For severe or refractory cases, bosentan may be considered.

Cutaneous Fibrosis: In early diffuse systemic sclerosis, treatment options include phototherapy and pharmacotherapy such as methotrexate or mycophenolate mofetil.

For severe or refractory fibrosis, cyclophosphamide or autologous hematopoietic stem cell transplantation (HSCT) may be necessary.

Calcinosis Cutis: Treatment options include carbon dioxide laser therapy or surgical removal of symptomatic lesions.

For scleroderma renal crisis: use of ACE inhibitors ( captopril ). 

For gastrointestinal disease: use proton pump inhibitors for GERD.GI motility disorder: prokinetic therapy, e.g., metoclopramide.

Cardiopulmonary disease requires targeted treatment for heart and lung conditions. 

 

 

Written by:

Atheer Alhuthaili, Medical Intern

Revised by:

Naif Alshehri, Medical Intern

References:

DermNet

Amboss 

Medscape 

Systemic Lupus Erythematosus (SLE)

Definition and Epidemiology:

Lupus Erythematosus is an autoimmune multisystem disorder that often affects the skin and other organs such as Kidneys, joints and heart. The cutaneous manifestations can be a source of disability.

Systemic lupus Erythematosus (SLE) is a common disease with significant morbidity and mortality. The reported prevalence of SLE in the United states is  20 to 150 cases per 100,000. The strongest affecting risk factor is gender. The increased frequency of SLE in women especially in the childbearing age has been attributed to the estrogen hormonal effect.

Ethnicity is also a major risk factor. The prevalence of SLE in African American women is fourfold higher than Caucasian women. In addition, African American and Hispanic individuals in the US have a poorer renal prognosis than Caucasian individuals.

Pathogenesis:

The pathogenesis of SLE is complex and multifactorial. It involves the interaction between genetic and environmental factors. The genetic factors include HLA-B8-DR3 and The environmental factors include ultraviolet radiation, medications, cigarette smoking and possibly viruses. This interplay triggers an inflammatory  cascade of cytokines, chemokines and inflammatory cell response that ends with cytotoxic keratinocyte damage.

Clinical features:

Discoid Lupus Erythematousus: discoid lesions represents one of the most common skin manifestations of lupus and commonly found on the face, scalp and ears. Discoid lesions has the potential of scarring, and over time, a substantial portion of patients develop disfiguring scars. Active lesions are intensely inflammatory with a pronounced superficial and deep dermal infiltrate. On palpation, they feel thicker and firmer than surrounding skin. The adnexa are prominently involved, with follicular plugging and scarring alopecia. Dyspigmentation is a common complication in longstanding lesions, with hypopigmentation in the center and hyperpigmentation in the periphery.

Subacute Cutaneous Lupus Erythematosus: patients with subacute cutaneous lupus Erythematosus (SCLE) typically exhibit photosensitivity. Their lesions most frequently occur in sun-exposed areas. Lesions of SCLE may have an annular configuration with raised pink borders and central clearing, or a papulosquamous presentation with chronic psoriasiform or eczematous appearance.

In 20-30% of patients with SCLE, the disease is linked to medications including terbinafine, thiazide diuretics, anti-TNF, and proton pump inhibitors.

Since Anti-SSA/Ro antibodies are associated with both Sjogren syndrome and SCLE. Some patients have features of both diseases and may have some internal manifestations of Sjogren such as pulmonary or neurologic disease.

Acute Cutaneous Lupus Erythematosus: the lesions of ACLE are exemplified by the development of Malar rash (“butterfly rash”). These lesions tend to be transient following sun exposure and resolve without scarring. Patients presenting with this type of eruptions must be carefully evaluated for internal manifestations.

The morphology of lesions ranges from mild erythema to intense edema. The face is most commonly affected and there is often sparing of the nasolabial folds.

Lupus panniculitis: intense inflammation of the subcutaneous tissue leading to indurated plaques that can evolve into disfiguring, depressed areas. Lesions are frequently distributed over the face, scalp, upper arms, breast and thighs.

Chilblain lupus: chilblain lupus consists of dusky purple papules and plaques on the toes, fingers and sometimes the nose. These lesions are exacerbated by cold exposure.

Systemic manifestations: the organ systems that are commonly affected are joints, kidneys, hematologic and Central nervous system as well as pleural and pericardial serosal surfaces. Many of the internal organs manifestaitons are included in the diagnostic criteria.

Diagnosis:

Diagnostic criteria: using the SLICC criteria, SLE is diagnosed if the patient has either of the following:

  • Four criteria including at least more than one clinical criterion and one immunological criterion
  • Biopsy proven lupus nephritis and antinuclear antibody (ANA) or anti double stranded DNA anitbody

Clinical criteria

  1. Acute or subacute cutaneous lupus
  2. Chronic cutaneous lupus (discoid, lupus panniculitis)
  3. Oral ulcers
  4. Nonscarring alopecia
  5. Synovitis involving 2 or more joints
  6. Serositis involving lungs and heart
  7. Renal involvement 
  8. Neurological involvement 
  9. Hemolytic anemia
  10. Leukopenia or lymphopenia
  11. Thrombocytopenia

Immunological criteria:

  1. Raised ANA titers
  2. Raised Anti-double stranded DNA
  3. Presence of anti smith antibody
  4. Positive antiphospholipid antibody
  5. Low complement levels
  6. Positive direct Coombs test

Management:

General measures:

  • Sun protection using clothing, accessories and SPF 50+ sunscreens.
  • Smoking cessation

Topical treatments:

  • Topical and intralesional corticosteroids are a mainstay of therapy. They offer a high degree of safety profile as well as a relatively rapid response. Particularly in active discoid lesions, intralesional triamcinolone can be very effective.
  • Topical calcineurin inhibitors such as Tacrolimus can also be used.

Systemic treatments:

  • Antimalarials such as hydroxychloroquine remains the gold standard for systemic therapy.
  • Systemic corticosteroids such as prednisone. These are the mainstay of treatment in acutely ill patients.
  • Methotrexate
  • Immunosuppressive agents such as azathioprine, mycophenolate and cyclophosphamide 
  • Targeted biological treatments that have been FDA approved such as anifrolumab and belimumab 

Written by: 

Bandar Alharbi, Medical Intern.

Revised by: 

Naif Alshehri, Medical Intern

Resources:

Dermnet

UpToDate

Bolognia

Hand eczema

Definition: 

Hand dermatitis, also known as hand eczema, is a common inflammatory skin condition affecting the palms and backs of the hands. 

It can be acute or chronic, often presenting with redness, thickened skin, scaling, swelling, and cracks. Chronic hand eczema (CHE) refers to cases lasting over three months or recurring frequently within a year.

 

Epidemiology: 

Hand dermatitis accounts for 20–35% of all dermatitis cases, though it is particularly common in young adult females it can occur at any age. It is more prevalent in individuals with a history of atopic dermatitis.

 Chronic hand eczema (CHE) affects an estimated 10–15% of the population, frequently observed in occupations involving wet work or chemical exposure.

 

Etiology: 

Hand eczema results from a combination of genetic and environmental factors:

  •  Genetic susceptibility (such as mutations in the filaggrin gene (FLG) impairs the skin barrier, leading to increased water loss and susceptibility to irritants and allergens.  
  • Environmental factors like repeated exposure to water, detergents, and chemicals, especially through occupational tasks. 
  • Additionally, allergic contact dermatitis can contribute to the condition. 

 

Clinical features: 

Hand eczema is typically bilateral, affecting both the palmar and dorsal surfaces of the hand. Common symptoms include burning, stinging, and itching. The condition can alternate between acute flare-ups, which cause redness, swelling, weeping, and the formation of vesicles, and a chronic phase that is marked by nail changes (such as cuticle loss, thickening of nail folds (chronic paronychia), and nail plate ridging), lichenification, dry, thickened skin, and fissures.

 

Diagnosis:

The diagnosis of hand eczema is primarily clinical and involves a comprehensive approach, starting with a detailed personal and occupational history to identify any personal or family history of atopy and potential exposure to irritants or allergens, A physical examination assesses the extent of hand involvement, along with a complete skin examination.

  • Patch testing is crucial for identifying allergens in patients with CHE unresponsive to treatment.  
  • Additional tests, such as skin prick tests, KOH preparation, and bacterial cultures, may be used to rule out other conditions. Also, in some cases, a skin biopsy is necessary to exclude other causes.

 

Management:

The management of hand eczema focuses on educating patients about proper Hand care, avoiding irritants and allergens, using non-soap cleansers, and applying thick emollients frequently.

  • For mild to moderate cases, high-potency topical corticosteroids are recommended, alongside liberal use of emollients. Steroid-sparing options like topical Calcineurin inhibitors (e.g., Tacrolimus) can also be used as an alternative.
  • In severe or unresponsive cases, a short course of oral corticosteroids may be necessary. Alternative treatments include phototherapy, oral immunosuppressants (such as methotrexate, cyclosporin, or azathioprine), or alitretinoin.
  • Dupilumab is an option for atopic CHE, and systemic antibiotics are prescribed if secondary bacterial infections are present. 

 

Written by: 

Raneem Alahmadi, Medical Intern.

Revised by: 

Naif Alshehri, Medical Intern

Resources:

Dermnet

UpToDate

 Seborrheic dermatitis

What is Seborrheic dermatitis?

Seborrheic dermatitis (SD) is a chronic inflammatory skin condition characterized by erythematous, scaly patches primarily in seborrheic areas—regions rich in sebaceous glands such as the scalp, face, and upper trunk. There are infantile and adult forms of seborrhoeic dermatitis.

 

 Who gets Seborrheic dermatitis?

Seborrhoeic dermatitis affects 3% to 12% of the population and has two main age distributions:   

Infants: Under 3 months old; usually resolves by 6-12 months.

Adults: It typically begins in late adolescence, is more common in males, and tends to peak during young adulthood and later in life. Various factors are linked to more severe cases in adults, including having oily skin, a family history of seborrhoeic dermatitis or psoriasis, and conditions causing immunosuppression, such as organ transplants, HIV, or lymphoma. Additionally, neurological and psychiatric disorders like Parkinson’s disease, depression, and epilepsy, as well as the use of neuroleptic medications, can contribute to its severity. Other contributing factors include PUVA therapy for psoriasis, lack of sleep, and stressful life events.

 

Causes of seborrhoeic dermatitis

The exact cause of seborrhoeic dermatitis is not fully understood. However, various factors are thought to be associated with the condition, including hormonal changes, fungal infections, nutritional deficiencies, and neurogenic factors. The proliferation of Malassezia yeast is believed to contribute to its development. Malassezia, a normal skin saprophyte, produces lipases and phospholipases that break down triglycerides in sebum into free fatty acids, which may trigger inflammation. Differences in skin barrier lipid composition and function may account for the varying manifestations of the condition. 

 

Clinical features of Seborrhoeic dermatitis

Infantile seborrhoeic dermatitis

Seborrhoeic dermatitis in infants, also known as cradle cap, features:

  • Diffuse, greasy, yellow scaling on the scalp.
  • The rash may extend to the armpit and groin folds.
  • Salmon-pink patches that may flake or peel.
  • Generally not itchy

Adult seborrhoeic dermatitis

Seborrheic dermatitis typically follows a chronic course characterized by episodic phases. Active phases may include symptoms such as burning and itching, while these are interspersed with inactive, asymptomatic periods. The condition usually flares in winter and improves with sun exposure in the summer. It manifests with a range of symptoms, from erythematous plaques with patchy scaling to greasy yellow crusts, and is commonly distributed in areas with hair and oily skin. The affected regions include:

  • Scalp (dandruff and itching)
  • Forehead/hairline and retro auricular area
  • Nasolabial fold, eyebrows, and periocular region (blepharitis with scaly, red eyelid margins)
  • Cheeks and chin
  • Presternal and interscapular regions
  • Axillae, under the breasts, umbilicus, and groin area

People with darker skin may show scaly, hypopigmented macules and patches in affected areas.

 

Diagnosis of Seborrhoeic dermatitis

Seborrhoeic dermatitis is usually diagnosed clinically based on lesion location, appearance, and behavior. If uncertain, a biopsy may be performed. Histological findings in seborrhoeic dermatitis typically include:

  • Parakeratosis in the epidermis
  • Plugged follicular ostia
  • Spongiosis (intercellular edema in the epidermis)
  • A sparse, perivascular, lymphohistiocytic inflammatory infiltrate in the dermis

 

Treatment of Seborrhoeic dermatitis

General Measures

  1. Patient Education:
    • Explain the nature of the condition and appropriate skincare routines.
  2. Lifestyle Modifications:
    • Diet: A high fruit intake may reduce symptoms.
    • Stress Management: Stress can trigger flare-ups, so managing stress is important.
  3. Many herbal remedies are used, but their effectiveness is unclear.

Specific Measures

  1. Keratolytics:
    • Salicylic Acid, Lactic Acid, Urea, Propylene Glycol: Used to remove scales.
  2. Topical Antifungal Agents:
    • Ketoconazole, Ciclopirox: Reduce Malassezia.
    • If resistant: Zinc Pyrithione or Selenium Sulfide.
  3. Mild Topical Corticosteroids:
    • Use for 1–3 weeks to reduce inflammation during acute flare-ups.
  4. Topical Calcineurin Inhibitors:
    • Pimecrolimus Cream, and Tacrolimus Ointment: Alternatives for long-term use, especially on the face.
  5. Resistant Cases in Adult :
    • Oral Itraconazole, tetracycline antibiotics, or phototherapy.
    • Low-Dose Oral Isotretinoin: Effective for severe cases.
  6. Roflumilast 0.3% Foam: Recently FDA-approved for use in patients aged 9 years and older.

 

Written by:

Atheer Alhuthaili, Medical Intern.

Revised by:

Naif Alshehri, Medical Intern.

References:

DermNet.

Amboss

Allergic Contact Dermatitis

Definition and epidemiology:

Allergic contact dermatitis (ACD) is a delayed type hypersensitivity reaction that is elicited when the skin is exposed with a substance to which an individual has been previously sensitized.  Allergic contact dermatitis accounts for 20% of the contact dermatitis, and it can affect individuals in all walks of life. 

 

Pathogenesis:

Allergic contact dermatitis is a T-cell mediated, delayed type hypersensitivity reaction. It’s an allergen-specific reaction that requires prior sensitization of the individuals to the chemicals. The pathogenesis involves 2 phases in which the initial sensitization phase when the individual comes in contact with the chemical, which penetrates the skin and triggers a cascade of events that leads to sensitization. The subsequent re-exposure of the skin leads to the presentation of the responsible allergen to the primed T-cell, causing release of multiple cytokines resulting in the clinical picture of eczema.

 

Clinical features:

Acute allergic contact dermatitis presents with erythematous, indurated, scaly plaques. Vesicle and bullae formation may occur in severe cases. 

Repeated or continuous exposure to the allergen results in chronic disease. The skin becomes dry, scaly and thickened as a results of acanthosis and edema.

Allergic contact dermatitis is typically localized to the area in which the skin is exposed to the chemical. For example:

  • Allergens applied to the scalp including hair dies and shampoos may elicit dermatitis in that area
  • Facial lesions may results from contact with cosmetic products 
  • Dermatitis involving the dorsal aspect of the foot suggests allergic contact dermatitis related to the shoe chemicals (rubber accelerators or potassium dichromate)
  • Periorificial allergic contact dermatitis involving the perioral, periocular and genital areas may be induced by fragrances, detergents or preservatives in hygiene products (moist wipes).

 

Diagnosis:

Clues from the clinical examination: The morphology, location and the course of dermatitis supports the diagnosis of allergic contact dermatitis. The typical appearance is well demarcated, pruritic, eczematous eruption localized to the area of skin that comes in contact with allergen.

History: A comprehensive history is helpful in aiding the diagnosis of allergic contact dermatitis. This includes reviewing the patient’s activities, hobbies, occupation and products used by the patient.

Health professionals, chemical industry workers, beauticians and hairdresser have an increased risk of developing occupational allergic contact dermatitis. A history of improvement during the weekends and holidays suggests an occupational origin.

Patch test: patch test is essential investigation in patients with persistent eczematous eruptions when contact allergy is suspected or cannot be ruled out. Patch test is based upon the principle that in sensitized individuals, primed antigen specific T lymphocytes circulating throughout the body and are able to recreate a delayed type hypersensitivity reaction when non irritating concentrations of the antigen are applied to normal skin.

 

Treatment:

Once the antigen has been identified, the patient should be given written information about the chemicals. The information sheet should include the name of the chemical, synonyms, typical uses, how to avoid exposure and alternatives. 

Although avoidance of the allergens is the mainstay of treatment, pharmacological treatment is required to achieve rapid control of symptoms in most cases. The treatment of allergic contact dermatitis follows the general principles of treating eczema including:

  • Emollients
  • Topical corticosteroids
  • Topical calcineurin inhibitors such as tacrolimus
  • Phototherapy (PUVA, narrow band UVB)
  • Systemic immunosuppressants such as azathioprine and methotrexate

 

Written by:

Bandar Alharbi, Medical Intern

Revised by:

Naif Alshehri, Medical Intern

Resources:

Dermnet

Uptodate

Bolognia

Atopic Dermatitis

Definition:

Atopic dermatitis, also known as atopic eczema, is the most prevalent inflammatory skin condition that is observed globally. It manifests as widespread dryness, itching, and a rash.

 

Epidemiology:

Approximately 230 million individuals worldwide suffer from atopic dermatitis, with a lifetime prevalence exceeding 15%, particularly in more affluent cultures. It usually impacts individuals who have a tendency for atopic conditions, which often tend to coincide with hay fever, asthma, and food allergies.

Typically, atopic dermatitis begins during infancy and can impact up to 20% of children. Around 80% of children who are affected experience the disease before they reach the age of 6. People of all age groups can be affected. 5–15% of young adults up to the age of 26 have it, despite the fact that it can settle in late childhood and adolescence.

 

Etiology:

Atopic dermatitis arises from a complex interaction of environmental and genetic aspects. 

Atopic dermatitis (eczema) is a complex condition with multiple factors contributing to its development, making it difficult to identify a single cause. There are numerous theories concerning the underlying mechanisms. Ongoing research is exploring various factors, including the immune system, mutations in skin structural genes, abnormalities in skin cells (keratinocytes), and the presence of bacteria, viruses, and yeasts on the skin surface.

 

Clinical features:

The hallmark symptoms of AD at every stage include dry skin and pruritus. Subacute and chronic AD is characterized by dry, scaly, or excoriated papules or skin thickening (lichenification) from persistent scratching, but acute AD is characterized by erythematous papules and vesicles with exudation and crusting. 

Clinical course and complications: AD progresses over months to years in a chronic, relapsing manner. Individuals who have mild disease may go through periods of intermittent flares followed by spontaneous remission. However, those with moderate to severe dermatitis typically do not experience complete clearance without receiving treatment.

 

Diagnosis:

The diagnosis of AD is clinical, which is established by evaluating the history, morphology, location of skin lesions, and related clinical symptoms. The diagnostic criteria include: 

  • Pruritus 
  • Eczematous dermatitis (acute, subacute, chronic) with characteristic morphology and age-specific patterns:

Facial, neck, and extensor involvement in neonates and young children

Flexural lesions in any age group, either present or past

Sparing the groin and axillary regions.

  • History of chronic or relapsing conditions

 

Management:

The primary objectives of managing atopic dermatitis (AD) are to alleviate symptoms (pruritus and dermatitis), avoid worsening of the condition, and minimize the potential risks associated with therapy. 

Management includes the removal of aggravating factors, restoration of the skin barrier function and moisturization of the skin, patient education, and pharmacological intervention for skin inflammation. 

  • Patient education is a crucial element of effective management. Patients are advised to: 

– Regularly apply emollients to maintain skin hydration. 

– Minimize aggravating elements such as: excessive bathing/washing without then moisturizing, exposure to cold, low-humidity conditions, excessive heat and perspiration, exposure to solvents, and strong detergents.

  • Patient with mild to moderate atopic dermatitis: 

Topical therapies: Patients presenting with mild to moderate symptoms are treated with topical treatments.

The recommendation for the majority of patients with mild to moderate AD is to use topical corticosteroids and emollients instead of other topical anti-inflammatory medications. 

Topical calcineurin inhibitors like pimecrolimus and tacrolimus are topical immunomodulators and work in a different way from corticosteroids, they are suitable for treating atopic dermatitis in sensitive sites such as the eyelids, skin folds, and genital area. It can be used interchangeably with topical corticosteroids.  

  • Patients with moderate to severe atopic dermatitis:

Patients with chronic, moderate to severe disease that does not improve with the best available topical therapy need a systemic treatment. For the majority of these patients, administration of a biologic immunomodulatory agent (dupilumab, tralokinumab, or lebrikizumab) instead of traditional immunosuppressants, other immunomodulators, or phototherapy is recommended 

 

Written by:

Mashael Alanazi, Medical Intern

Revised by:

Naif Alshehri, Medical Intern

Resources:

DermNet

UpToDate

Sturge–Weber syndrome

What is Sturge–Weber syndrome?

Sturge-Weber syndrome (SWS), also known as encephalotrigeminal angiomatosis, is a neurocutaneous disorder characterized by capillary malformation on the facial skin and capillary-venous malformations in the brain and eyes. A facial cutaneous venous dilatation, often known as a nevus flammeus or port-wine birthmark, is a hallmark of SWS.

 

Causes of Sturge–Weber syndrome

Sturge-Weber syndrome is caused by a somatic mosaic mutation in the GNAQ gene on chromosome 9. This indicates that the gene mutation occurred in body cells following the formation of the zygote. GNAQ regulates intracellular signaling pathways. In affected cells, the mutation causes uncontrolled formation or maturation of capillaries. 

 

Clinical features of Sturge–Weber syndrome

Sturge-Weber syndrome is marked by vascular malformations on the face as well as in the eye and brain of affected individuals. These are present at birth.

Port-wine stains are the most frequent type of vascular malformation, affecting around three in every 1000 infants, but most are not associated with Sturge–Weber syndrome. 

  • It is frequently the first component of the disease to be noticed because it is apparent at birth. It may be extremely pale at first, but it normally darkens with age. 
  • It typically appears on the forehead and upper eyelid, where the first and second divisions of the trigeminal nerve run. 
  • It can also impact both sides of the face. Leptomeningeal vascular malformations arise inside the brain on the same side as the port-wine stain. It may also occur without a port-wine stain.

Neurological and ophthalmological symptoms are progressive and typically appear in the first two years of life. These may include:

  • Seizures and Epilepsy
  • Hemiparesis and stroke-like events 
  • Behavioral problems
  • Visual field defects and glaucoma.
  • Growth hormone deficiency.

 

Diagnosis of Sturge–Weber syndrome

Sturge-Weber syndrome is diagnosed by identifying the characteristic trigeminal port-wine stains and leptomeningeal capillary-venous malformations. A diagnosis based on leptomeningeal lesions alone depends on the development of symptoms.

 If neurological symptoms or abnormalities are present, magnetic resonance imaging (MRI) of the brain with gadolinium contrast is performed to detect leptomeningeal capillary-venous malformations.

 

Differential diagnosis of Sturge–Weber syndrome:

Here is a list of vascular malformation syndromes with its characteristics:

  • Klippel–Trénaunay syndrome is characterized by extensive capillary malformations that primarily affect the limbs and trunk, often leading to hypertrophy of the involved limb. 
  • Proteus syndrome manifests as asymmetrical and disproportionate overgrowth of various body parts, caused by a somatic activating mutation in the AKT1 oncogene. 
  • Parkes–Weber syndrome features large capillary malformations on extremities, accompanied by hypertrophy and multiple fast-flowing arteriovenous shunts. 
  • CLOVES syndrome is identified by congenital lipomatous overgrowth, vascular malformations, epidermal nevi, and spinal or skeletal anomalies, including scoliosis. It results from somatic mosaic activating mutations in the PIK3CA gene.

 

Treatment of Sturge–Weber syndrome

Sturge-Weber syndrome has no specific treatment. Treatment focuses on managing the cutaneous, neurological, and ocular symptoms.

  • Treatment of seizures in patients with Sturge–Weber syndrome often proves challenging, as antiepileptic drugs do not always yield effective results. Currently, no specific treatment has been identified as consistently superior to others. 
  • Port-wine stains associated with the condition can be addressed using pulsed-dye laser therapy, although the outcomes are variable. Given the generally limited success of pulsed-dye lasers alone, adjunctive treatments involving topical antiangiogenic agents are being trialled. 
  • Regular ophthalmologic evaluations are advised due to the frequent occurrence of glaucoma in Sturge-Weber syndrome, which is managed through both surgical and medical interventions. 
  • Infants diagnosed with Sturge–Weber syndrome should receive low-dose aspirin therapy as this approach may help prevent disease progression by enhancing cerebral blood flow and potentially reducing the risk of neuronal damage. 

 

Written by:

Atheer Alhuthaili , Medical Student.

Revised by:

Naif Alshehri, Medical Intern.

References:

DermNet.

Picture Reference:

Bolognia Dermatology 5th Edition.

Neurofibromatosis type 1

Definition and epidemiology:

Neurofibromatosis type 1, also called Von Recklinghausen’s disease, is a genetic disorder characterised by cutaneous as well as peripheral and/or central nervous system neoplasms. Neurofibromatosis type 1 incidence rate is approximately 1 in 3000 births.

 

Pathogenesis:

Neurofibromatosis type 1 is inherited in an autosomal dominant pattern. 50% of patients have de novo mutations that occur in paternally derived chromosomes. 

NF1 is caused by pathogenic variants of NF1 gene, located in chromosome 17q11.2. The gene encompasses a protein called neurofibromin.

 

Clinical features: 

The clinical features of NF1 are myriad and vary in frequency.

 

Café-au-lait macules– are flat, uniformly hyperpigmented macules that appear during the first year after birth and usually increase in number during early childhood . The number of café-au-lait macules then stabilizes over time. Up to 15 percent of the general population has one to three café-au-lait macules; however, the presence of six or more café-au-lait macules is highly suggestive of NF1. Approximately 95 percent of adults with NF1 have café-au-lait macules, but they tend to fade later in life and may be difficult to distinguish in older individuals.

Freckling– Freckling in the axillary or inguinal regions (Crowe sign) is a diagnostic criterion distinct from café-au-lait macules. Freckling usually is not apparent at birth but often appears by age three to five years, typically first in the inguinal region.

Lisch nodulesLisch nodules are raised, tan-coloured hamartomas of the iris and represent a specific finding for NF1. 

NeurofibromasNeurofibromas are the most common type of benign tumour that develops in people with NF1. Neurofibromas are benign peripheral nerve sheath tumours that are composed of a mixture of Schwann cells, fibroblasts, perineurial cells, mast cells, macrophages, and T cells.

  • Cutaneous neurofibromas: are  skin-coloured  to  pink,  tan,  or  brown  papulonodules  that  are  soft  or slightly  rubbery  in  texture  and  can  range  from  a  few  millimetres  to several  centimetres  in  diameter.  While  fully  formed  CNFs  are  often dome-shaped  or  pedunculated,  early  lesions  may  be  barely  elevated. They  invaginate  easily  with  gentle  pressure,  exhibiting  the  pathogno- monic “buttonhole” sign.
  • Subcutaneous neurofibromas occur deeper in the dermis and subcutis, tending to be firmer and less well-circumscribed than cutaneous neurofibromas.
  • Plexiform neurofibromas may track along nerves to create tender, firm nodules or masses in the subcutaneous tissue with a  “bag  of  worms”  consistency  upon  palpation.

Neurological manifestations – these include optic gliomas, learning difficulties, speech problems and behavioural issues.

Skeletal manifestations – Macrocephaly,  hypertelorism,  scoliosis, and  osteopenia  are common  cranioskeletal  abnormalities  in  individuals  with  NF1.  A highly distinctive but less common finding is pseudarthrosis of the long bones, most often the tibia. Sphenoid wing dysplasia is a congenital, typically unilateral bony defect in the posterior wall of the orbit.

Cardiovascular manifestations – Hypertension is a common finding in NF1 patients. Although essential hypertension  is  most  frequent,  renovascular  stenosis  (especially  in children)  and  unsuspected  pheochromocytomas may  be  the  cause in  some  patients. Pulmonary stenosis can occur in 1% of NF1 patients.

 

Diagnosis:

The diagnosis of NF1 is based upon the presence of characteristic clinical features. Genetic testing is not required to make the diagnosis but can be helpful in establishing the diagnosis in children who do not meet diagnostic criteria.

Diagnostic criteria – Two or more of the following must be present:

  • Six or more café-au-lait macules >5 mm in prepubertal individuals and >15 mm in postpubertal individuals. 
  • Two or more neurofibromas of any type or one plexiform neurofibroma.
  • “Freckling” in the axillary or inguinal regions.
  • Optic gliomas.
  • Two or more Lisch nodules (iris hamartomas).
  • Osseous lesions, such as sphenoid wing dysplasia or thinning of long bone cortex, with or without pseudarthrosis .
  • First-degree relative (parent, sibling or offspring) with NF1 by the above criteria.

 

Management: 

Management of patients with NF1 requires a multi-disciplinary approach. Dermatologists  are  often  consulted  to  assist  in  establishing  the diagnosis in  affected  children. Goals  of  longitudinal  care  include  early  recognition  and  treatment  of complications, maximization of academic and vocational achievement, and minimization of the disease’s psychosocial impact. 

Plexiform neurofibromas (PNF)  may  grow  into  large,  bulky  tumors  during early  childhood.  Multidisciplinary  teams  are  often  required  to  excise deep  and  extensive  neurofibromatous  tissue,  and  the  lesions  tend  to recur  following  surgery.

Café-au-lait macules do  not  need  or  respond  well  to  treatment,  although  it  may  be  desired  for  cosmetic  purposes.  When  laser therapy  is performed,  CALMs  tend  to  persist  or  recur.

Lifelong  surveillance  for  the  development  of  Malignant peripheral nerve sheath tumors (MPNST)  is  essential, particularly for patients at increased risk of this malignancy due to the known presence of PNFs, polyneuropathy secondary to multiple nerve root  tumors,  a  history  of  radiation  therapy,  or  a  germline  NF1  microdeletion. PET- CT scan can aid in the early detection of malignant change within Plexiform neurofibromas.

 

 

Written by:

Bandar Alharbi, Medical Intern

Revised by:

Naif Alshehri, Medical Intern

Resources: 

Dermnet

UpToDate

Bolognia Dermatology textbook

 

Tuberous sclerosis 

Definition:

Tuberous sclerosis is a hereditary condition characterized by the presence of hamartomas in multiple organs, but specifically the skin, brain, eye, kidney, and heart. Hamartomas are benign malformations characterized by excessive proliferation of cells and tissues that are typically found in the affected region, including naevi (birthmarks). Tuberous sclerosis is also referred to as epiloia.

 

Etiology:

Tuberous sclerosis is a hereditary condition caused by a mutation in either of two genes:

  • TSC1 gene is responsible for the production of hamartin protein in 10-30% of cases
  • TSC2 gene is responsible for the production of tuberin protein

Around one-third of all cases of tuberous sclerosis are passed down from a parent who has the condition. Most other cases arise from sporadic new mutations that occur during early development, with TSC2 mutations being the most common.

 

Clinical features:

  • Cutaneous lesions— Almost all individuals with TSC exhibit one or more of the skin lesions that are distinctive of the condition. The predominant cutaneous manifestations observed in TSC include hypomelanotic macules, angiofibromas, shagreen patches and fibrous plaques.

 

  • Hypomelanotic macules also referred to as ash-leaf spots: These are typically elliptical in shape and may need to be examined using a Wood’s lamp (ultraviolet light) in order to be seen. 

It can manifest either at birth or during early infancy.

The presence of three or more white spots at birth indicates a diagnosis of tuberous sclerosis.

 

  • Fibrous cephalic plaques: These are unique brown fibrous plaques that can be easily identified on the forehead. They are often the first noticeable characteristic of TSC when examining affected newborns and infants. 

Hypomelanotic macules and fibrous cephalic plaques generally manifest at an earlier stage compared to facial angiofibromas or ungual fibromas.

 

  • Angiofibromas: These are benign tumors that commonly occur in the malar regions of the face. They are also referred to as fibroadenomas.

Typically manifest between the ages of 3 and 10 and progressively grow in size and quantity until adolescence. 

Additionally present on the nails, scalp, and forehead.

 

  • Shagreen patches: These are connective tissue nevi, which are typically observed on the lower back.

 

  • Ungual fibromas: also referred to as periungual or subungual fibromas (Koenen tumors).

Smooth, firm, flesh-colored lumps that appear from the nail folds.

Periungual sites, which are located around the nail, are more prevalent compared to subungual sites, which are found under the nail.

More frequently found on the feet rather than the hands.

 

  • Other organ involvement Tuberous sclerosis is associated with epilepsy in approximately 70% of cases. Typically, it starts during infancy or early childhood and can occur before the development of skin lesions by several years.
  • Developmental delay and behavioral problems may also arise. Manifestations include a range of cognitive impairments, including mild to severe intellectual disability, as well as conditions such as autism, attention deficit disorder (ADD), anxiety, depression, paranoia, and schizophrenia.
  • Other manifestations of tuberous sclerosis include ocular involvement with white spots on the iris and retina,and also tumors in the heart, gastrointestinal system, and kidneys, and other pulmonary manifestations.

 

Diagnosis:

Genetic criteria : Based on genetic criteria, the presence of a TSC1 or TSC2 pathogenic variant in nonlesional tissue is enough to confirm a diagnosis of TSC, regardless of any clinical findings. 

 

Clinical criteria : The clinical criteria for TSC consist of 11 major features and 7 minor features.

 To diagnose definite TSC, there must be either two major features or one major feature along with two or more minor features.

 

Major features – The following are major clinical features of TSC:

  • Hypomelanotic macules (≥3, at least 5 mm diameter)
  • Angiofibromas (≥3) or fibrous cephalic plaque
  • Ungual fibromas (≥2)
  • Shagreen patch
  • Multiple retinal hamartomas
  • Multiple cortical tubers and/or radial migration lines
  • Subependymal nodules (≥2)
  • Subependymal giant cell astrocytoma
  • Cardiac rhabdomyoma
  • Lymphangioleiomyomatosis (LAM)
  • Angiomyolipomas (≥2)

 

Minor features – The following are minor clinical features of TSC:

  • Confetti skin lesions (1 to 2 mm hypomelanotic macules)
  • Dental enamel pits (≥3)
  • Intraoral fibromas (≥2)
  • Retinal achromic patch
  • Multiple renal cysts
  • Nonrenal hamartomas
  • Sclerotic bone lesions

 

Management:

Tuberous sclerosis is a condition that affects multiple systems in the body, so in its management it typically requires a multidisciplinary approach.

Some patients may find skin lesions, especially facial angiofibromas, to be psychologically distressing. Angiofibromas can be effectively removed using laser treatment or electrosurgery.

The topical mTOR inhibitor sirolimus 0.2% gel, also known as rapamycin, showed potential in reducing angiofibromas. 

 

 

Written by:

Mashael Alanazi, Medical Intern

Revised by:

Naif Alshehri, Medical Intern

Reference:

DermNet

UTD