Nodular Prurigo

Nodular prurigo (NP), also known as prurigo nodularis, is a chronic dermatological disorder characterized by intensely pruritic, firm nodules. Although it can form anywhere on the body, a symmetrical distribution of arms, legs, back, and torso is where it most frequently appears.

 

Etiology:

It is still unclear what specifically causes NP. Based on skin biopsies, it is believed to be related to a dysregulation of the nerves, with more nerve cells seen in the dermis and fewer in the epidermis. 

There is also an association with atopy, certain drugs, and systemic conditions such as chronic kidney disease, liver disease, diabetes, and malignancy.

 

Clinical features:

The severity of NP can range from a few to hundreds of lesions of different sizes.

At first, the rash:

– Include tiny, red, or pink bumps typically 3–8 mm in diameter.

– Has a hyperpigmented border

– Very itchy 

– Is distributed in readily accessible body regions, including the lateral aspects of the arms and legs, shoulders, chest, and buttocks.

Sometimes, it begins as a papule and progresses to a nodule or plaque.

Scratching results in:

-Enlargement producing a raised, warty, nodular surface. The nodules have a symmetrical distribution and are usually hard and small, but they can reach up to 3 cm in diameter.

-Ulceration of the skin that can lead to an increased risk of infection.

-Healed lesions may leave a scar or discoloration.

 

Diagnosis:

The diagnosis of NP is clinical, based upon the clinical presentation of distinctive excoriated, nodular lesions frequently distributed symmetrically and a patient’s history of persistent, intense pruritus. A skin biopsy is not routinely performed to confirm the diagnosis.

It is essential to evaluate systemic causes of persistent pruritus in individuals with NP who do not have a history of atopic dermatitis or other pruritic skin disorders. These causes may include chronic kidney disease, liver disease, thyroid disease, HIV infection, parasite infestation, or malignancy. The initial laboratory and imaging evaluation may consist of:

  • Complete blood cell count
  • Liver function tests
  • Blood urea nitrogen and creatinine
  • Thyroid-stimulating hormone
  • HIV test
  • Urinalysis
  • Stool examination for ova and parasites
  • Chest radiograph

 

Management:

A complex and multi-modal strategy is necessary for the treatment of NP which includes:

  • Instructing patients on various ways to reduce skin itching and scratching 
  • Treating pruritus symptoms 
  • Topical or systemic therapies that target the itch-scratch cycle and minimize skin lesions

Common treatment options include: 

  • Topical emollients
  • Topical steroid cream or ointment — usually ultrapotent steroid and applied under hydrocolloid dressing or paste bandage occlusion, or steroid impregnated tape
  • Topical capsaicin and tacrolimus 0.1% ointment for itch
  • Local corticosteroid injection into the nodules to reduce inflammation
  • Sedating oral antihistamines
  • Phototherapy with either UVB or photochemotherapy (PUVA)
  • Systemic treatment with gabapentin, pregabalin, and naltrexone
  • Occasionally, antibiotics may be used to treat locally infected skin (cellulitis).

 

Written by:

Mashael Alanazi, Medical student.

Revised by:

Maee Barakeh, Medical student.

References:

DermNet

Uptodate

Molluscum Contagiosum

It is a benign, often asymptomatic viral infection of the skin, with no systemic manifestation. It is caused by molluscipoxvirus, a part of the poxviridae family which is a family of double-stranded DNA viruses. It is most common in childhood and early adolescence. 

 

Risk Factors:

As mentioned, the etiology is due to molluscipoxvirus, but we have several risk factors associated with this disease. These risk factors include immunosuppression state, active atopic dermatitis, hot and humid climates, and crowded living conditions. Generally, those with poor immune function and immunocompromised skin are at risk for molluscum contagiosum.

 

Mode of Transmission:

Molluscum contagiosum can be transmitted due to direct contact during sports or other activities including sexual contact, indirect skin contact, or with fomites which are any object that can transmit the organism. Lastly, auto-inoculation can transmit the lesion by scratching or any trauma resulting in linear lesions (Pseudo koebner phenomenon).  

 

Clinical Features:

The incubation period will usually be 2-6 weeks or more. Usually, the patient will come complaining of single or multiple non-tenders, skin-colored, pearly, dome-shaped papules with central umbilication. The lesion will be 2–5 mm in diameter and contain a caseous plug which if you squeeze will produce white cheesy fluid that consists of molluscum bodies. 

The usual lesions in children will be the face, trunk, and limbs, in contrast to adults where the lesions will be usually in the abdomen, inner thighs, and genitalia. Finally, patients with HIV will usually have widespread and large (more than 15 mm) lesions. 

 

Diagnosis:

Molluscum contagiosum is usually recognized by its characteristic clinical appearance (dome-shaped papules, often with central umbilication), and is distinctive on dermatoscopy which will show white molluscum bodies can often be expressed from the center of the papules. Sometimes, the diagnosis is made on skin biopsy. Histopathology will show the following features, acanthosis, cup-shaped invagination, and molluscum bodies (Henderson-Paterson bodies) which are keratinocytes with eosinophilic intracytoplasmic inclusion bodies containing viral particles. 

 

Management:

Spontaneous remission is expected, however active treatment is considered in sexually transmitted molluscum, immunocompromised individuals or upon parental request.  

The first line of treatments includes cryotherapy and curettage which has an immediate resolution of the lesion. Both treatments  are well tolerated by adults.

Cantharidin which is a blistering agent can be applied directly to lesions, and a small blister will form which will result in the disappearance of the lesion and healing without scarring. Podophyllotoxin can also be used directly on the skin. 

Immunocompromised patients or individuals with refractory disease will usually benefit from Cidofovir, Interferon-α, and Imiquimod. Other treatments for molluscum include potassium hydroxide, salicylic acid, topical retinoids, oral cimetidine, and pulsed dye lasers.

 

Complications: 

It includes secondary bacterial infection from scratching, conjunctivitis, disseminated secondary eczema, and scarring.

 

Prevention: 

Patients should be instructed to do the following, keep good hygiene, cover the lesion, do not share towels, clothing, or other personal items, and avoid sexual activity until the resolution of the lesion.

 

 

Written by:

Mohammed Alahmadi, Medical Student. 

Revised by:

Maee Barakeh, Medical Student. 

References:

DermNet

Dermatology Essentials by Bolognia

Fitzpatrick’s Color Atlas and Synopsis of Clinical Dermatology

UpToDate  

Keratoacanthoma

Keratoacanthoma (KA) is a commonly encountered skin tumor that presents a captivating clinical challenge due to its rapid growth and locally destructive nature. While some cases of KA may regress spontaneously, they often leave behind visible scarring. However, the clinical presentation of KA can closely resemble well-differentiated squamous cell carcinoma (SCC), leading to unpredictability in its course.

Pathophysiology:

The precise pathophysiological mechanisms underlying keratoacanthoma are not fully understood. However, it is widely believed to arise from the hair follicles or the sebaceous glands. Several hypotheses have been proposed, including the role of ultraviolet radiation, genetic factors, viral infections, and immune dysregulation in the development of keratoacanthoma.

Clinical Features:

Keratoacanthoma typically presents as a rapidly growing dome-shaped nodule with a central crater filled with keratin debris. It commonly occurs on sun-exposed areas of the body, such as the face, scalp, ears, and dorsum of the hands. Initially, the lesion may resemble a pimple or a wart, but it rapidly enlarges over a period of weeks to months. The growth phase is followed by a stabilization phase, during which the lesion may persist for several months before spontaneously regressing.

Diagnosis:

The diagnosis of keratoacanthoma is primarily based on clinical examination and histopathological evaluation. A thorough physical examination, including a dermatoscopic assessment, can aid in distinguishing keratoacanthoma from other skin lesions. Dermoscopy often reveals a central plug, keratin-filled crater, and peripheral keratotic rim. To confirm the diagnosis, a skin biopsy is performed, and the specimen is sent for histopathological analysis. Microscopically, keratoacanthoma is characterized by a well-demarcated cup-shaped lesion with a central keratin-filled crater, hyperkeratosis, and proliferation of keratinocytes.

Management:

The management of keratoacanthoma depends on various factors, including the size, location, and individual patient characteristics. Several treatment options are available, and the choice of therapy should be tailored to the specific case. Here are some commonly employed management strategies:

1. Observation: In some cases, keratoacanthomas may undergo spontaneous regression without any intervention. Close observation with regular follow-up visits may be appropriate for small, asymptomatic lesions in low-risk areas.

2. Surgical Excision: Surgical excision is a commonly employed treatment modality for keratoacanthoma. It involves complete removal of the lesion with a margin of healthy tissue to reduce the risk of recurrence. This approach is particularly suitable for larger or symptomatic tumors.

3. Mohs Micrographic Surgery: Mohs surgery is a specialized technique that ensures the highest cure rate while preserving as much healthy tissue as possible. It is often recommended for lesions in cosmetically sensitive areas or those with aggressive features.

4. Topical Therapies: In select cases, topical treatments such as imiquimod cream or 5-fluorouracil may be employed. These medications stimulate the immune system or inhibit cell proliferation, leading to tumor regression.

5. Cryotherapy: Cryotherapy involves freezing the lesion with liquid nitrogen. It is commonly utilized for smaller keratoacanthomas and can be performed in an outpatient setting.

Written by:

Deemah AlHuraish, medical student.

Revised by:

Maee Barakeh, medical student.

References:
DermNet

NCBI

AOCD

Cold Urticaria

Cold urticaria is one type of chronic inducible urticaria that is relatively uncommon. Exposure to cold air, water, or objects cause the development of urticarial weals.

Epidemiology:

About 0.05% of the population develops cold-induced urticaria over time. Though often diagnosed in people of young and middle-age, it may also manifest in children and the elderly. It is twice as common in females as in males.

Etiology: 

Cold urticaria is a condition that arises as a result of exposure to low temperatures. The mechanism by which the cold stimulus induces the activation of mast cells and the subsequent release of histamine, along with other inflammatory mediators, remains unclear.

Cold urticaria can manifest as either primary (idiopathic) or due to an underlying hematologic or infectious illness. The majority of cases fall under the category of idiopathic, meaning that the cause is unknown.

Clinical features:

The symptoms of cold urticaria manifest within a time frame of 2 to 5 minutes following exposure and often persist for a duration of 1 to 2 hours.

Urticaria and angioedema can manifest as either localized, affecting specific areas of the body, or generalized, resulting in a rash that covers the entire body.

Systemic reactions, from mild discomfort to anaphylaxis, have been linked to prolonged exposure to cold, such as when swimming in cold water. Cold-water aquatic activities are dangerous because of the risk of anaphylaxis and secondary drowning.

Patients undergoing surgery under general anesthesia or in cold rooms are also at risk for developing severe reactions.

Diagnosis:

The diagnosis of cold urticaria may be established with the application of an ice cube to the skin of the forearm for a duration of 1 to 5 minutes. If the patient has cold urticaria, it is expected that a clearly discernible red and swollen rash would develop within a few minutes in the region that has been subjected to the cold-stimulation test.

Associated illnesses may also be identified by doing complete blood count and metabolic testing.

Treatment:

It is important for patients with cold urticaria to take precautions against experiencing a sudden decrease in body temperature. Supervision is required at all times during any aquatic activity (including swimming and surfing).

Patients at risk for anaphylaxis should always have access to adrenaline.

Non-sedating antihistamines at large dosages (up to 40 mg of cetirizine daily, for instance) may be useful. A brief course of oral glucocorticoids may help patients with severe angioedema.

Cautious induction of cold tolerance may be effective (desensitization) by progressively hardening the skin to cold temperatures and then exposing the skin to it frequently, for example, by taking regular cold showers.

Written by:

Mashael Alanazi, medical student

Revised by:

Maee Barakeh, medical student

Resources:

DermNet

UpToDate

Merkel Cell Carcinoma

Merkel Cell Carcinoma, also known as cutaneous neuroendocrine carcinoma, is a rare and aggressive form of skin cancer with a high risk for recurring and metastasizing. It occurs almost exclusively in white skin, and is slightly more common in males.

Etiology:

Approximately 80% of examined Merkel cell carcinomas have Merkel cell polyomavirus (MCPyV) identified. It is believed that when immune function is compromised, the virus induces gene alterations that result in Merkel cell cancer.

Because virus-negative tumors typically develop on skin that has been exposed to the sun, they are linked to high UV radiation exposure. One major contributing factor to the development of Merkel cell carcinomas is immunosuppression.

It was once thought that Merkel cells, which are skin pressure receptors, were the source of Merkel cell cancer. Based on clonal immunoglobulin chain rearrangement, early B-cell markers expressed, and cellular shape, a new study suggests that their ancestors were lymphocytes.  

Clinical features:

Typically, asymptomatic, non-tender, solitary, uneven red nodule that is rapidly growing is the first sign of Merkel cell cancer. Although it grows far more quickly, it frequently resembles other, more prevalent skin malignancies in appearance, such as basal cell carcinoma.

Multiple metastases may form surrounding the primary tumor in Merkel cell tumors, which spread through the lymphatic system and can cause a local recurrence. Additionally, it may spread to axillae, groin, and neck lymph nodes.

The rate of recurrence  is markedly higher than that for invasive melanoma, squamous cell carcinoma, or basal cell carcinoma. The majority of recurrences happen in the first two years following diagnosis.

Diagnosis:

Any tumor exhibiting the following clinical characteristics, which are seen in roughly 90% of patients, should be ruled out as being likely to be Merkel cell carcinoma. These characteristics can be remembered using the acronym “AEIOU”:

  • Asymptomatic or non-tender
  • Expanding rapidly
  • Immune suppressed
  • Older than 50
  • UV-exposed fair skin

A tumor biopsy is the primary test. This demonstrates the typical histology of Merkel cell cancer. Since thyroid transcription factor (TTF1) is typically negative and cytokeratin-20 (CK20) is positive in up to 95% of tumors, immunohistochemistry can be useful.

If the tumor has progressed to other places, a general examination, including assessment of the local lymph nodes, and staging studies may be scheduled. Imaging modalities, lymph mode ultrasound scanning, and sentinel node biopsies are examples of staging investigations. 

Management:

Treatment options include excision or Mohs surgery.  Except in very small lesions, radiation therapy is usually administered to the Merkel cell carcinoma site along with regional lymph node placement.

Pembrolizumab and nivolumab, immune checkpoint inhibitors for advanced Merkel cell carcinoma, up to 50% of patients have shown positive response. Avelumab, another PD-1/PD-L1 medication, received expedited approval from the US Food and Drug Administration in March 2017 to treat metastatic Merkel cell carcinoma.

Prognosis: 

Five-year survival rates are overall 30–50%. Survival rates are better for patients initially diagnosed with Stage 1 Merkel cell carcinoma and in younger patients than when it has already metastasized or patients are over 80 years of age. 

Written by:

Mohammed Alahmadi, Medical Student. 

Revised by:

Maee Barakeh, Medical Student. 

References:

DermNet

Fitzpatrick’s Color Atlas and Synopsis of Clinical Dermatology

Review of Dermatology by Ali Alikhan

Hand, Foot, and Mouth Disease

Hand, foot, and mouth disease (HFMD, also called enteroviral vesicular stomatitis is a common acute viral infection, primarily affecting young children under the age of 5. It is known to appear in a characteristic distribution, involving mucocutaneous lesions over hands, feet and oral cavity.

Etiology:

HFMD transmission is very rapid, mainly via  direct contact with the blister fluid or droplets spread from the mouth.

Numerous coxsackie virus serotypes have been implicated to cause HFMD, most commonly type A16.  Enterovirus 71 infection has been associated with cardiopulmonary and neurologic complications and even deaths in affected young children.

 

Clinical Features:

Patients with HFMD often present with fever and malaise, and they may have a mild prodrome prior to the onset of the exanthem.

HFMD exanthem is characterized by:

  •  vesicular eruption on the palms and soles. The dorsal aspect of the hands and feet may be involved as well as the buttocks and perineum. The lesions are typically tender and are usually oval rather than round.
  • Oral lesions are most common on the tongue, buccal mucosa, palate, uvula, and anterior tonsillar pillars. They are usually painful, especially with oral intake.
  • Onychomadesis occasionally occurs months after HFMD as a consequence of temporary nail matrix arrest related to the viral infection.

 

Complications: 

HFMD rarely causes serious complications. Enterovirus 71 is usually associated with more severe infections and complications, especially among immunosuppressed individuals or neonates. Rare serious reported complications include myocarditis, meningoencephalitis, and pulmonary edema.

 

Diagnosis:

HFMD is diagnosed clinically based on exposure history, geographic location, and clinical signs and symptoms.

Confirmation of an enteroviral infection may be accomplished by viral testing from vesicular fluid via reverse transcription polymerase chain reaction (RT-PCR)-based assays to determine  the specific type of enterovirus, however, it is done only for research and public health purposes. 

 

Management:

HFMD is a self-limiting disease  with spontaneous resolution typically within 1–2 weeks. Supportive care is the mainstay of treatment, including hydration, analgesic and blister care.

Pleconaril has been demonstrated in recent research and has shown a promising outcome for serious enteroviral infections. It is a specific antiviral therapy that interferes with enterovirus attachment and uncoating by binding to the protein capsid.

 

Written by:

Maee Barakeh, medical student.

References:

Bolognia textbook of dermatology

DermNet

Acrodermatitis Enteropathica

Acrodermatitis enteropathica (AE) is a rare genetic disorder characterized by impaired zinc absorption, resulting in zinc deficiency. This condition affects the skin, gastrointestinal system, and immune system.

 

Pathophysiology:

Acrodermatitis enteropathica is primarily caused by mutations in the SLC39A4 gene, which encodes for the zinc transporter protein known as ZIP4. This protein plays a crucial role in facilitating the absorption of dietary zinc from the intestines into the bloodstream. Mutations in the SLC39A4 gene lead to impaired zinc uptake, resulting in zinc deficiency despite an adequate zinc intake.

 

Clinical Features:

Clinical manifestations usually appear within 1 to 2 weeks after weaning or at 4 to 10 weeks of age if bottle-fed.

Acrodermatitis enteropathica is characterized by a classic triad of symptoms, including periorificial dermatitis, diarrhea, and alopecia. 

  1. Periorificial Dermatitis:

The rash in acrodermatitis enteropathica typically presents with a distinct distribution. The periorificial rash is commonly observed in a horse-shoe or U-shaped pattern, involving the areas around the mouth and eyes, while sparing the lips. There is usually a sharp demarcation between the affected area and normal skin, creating a noticeable contrast. The rash may manifest as eczematous or psoriasiform plaques that can progress to include vesicles, bullae, pustules, erosions, or hyperkeratotic areas.

  1. Diarrhea:

Diarrhea is a common symptom in acrodermatitis enteropathica and is often chronic in nature. 

  1. Alopecia:

Another characteristic feature of acrodermatitis enteropathica is diffuse hair loss, which affects the scalp, eyebrows, and eyelashes. The hair loss may be patchy or diffuse and is attributed to the disruption of hair follicle development and maintenance due to zinc deficiency.

 

In addition to the triad, acrodermatitis enteropathica can present with various additional cutaneous manifestations. These include glossitis, characterized by a red and glossy tongue, along with mouth ulcers and angular cheilitis. Symmetrical peri-anal excoriations and a rash on the buttocks can also occur. Zinc deficiency can impair wound healing, resulting in delayed healing of cuts and abrasions. Nail changes, such as softness, ridging, abnormal growth, and inflammation of the nail fold (paronychia), may also be observed.

While the noncutaneous symptoms of acrodermatitis enteropathica include blepharo-conjunctivitis, sensitivity to light, loss of appetite, irritability, depressed mood, growth failure in untreated children, hypogeusia, and hypogonadism in male adolescents and young adults.

 

Diagnosis:

The diagnosis of acrodermatitis enteropathica is primarily based on clinical features and confirmed by laboratory tests. A thorough physical examination, including a detailed evaluation of the skin and mucous membranes, can provide valuable diagnostic clues. Additionally, a detailed medical history, including feeding patterns and response to zinc supplementation, is essential.

Laboratory investigations play a crucial role in confirming the diagnosis. Blood tests can reveal low serum zinc levels, which is a strong indicator of zinc deficiency.

 

Management:

The management of acrodermatitis enteropathica involves lifelong zinc supplementation to correct the underlying deficiency. Zinc supplementation can be administered orally or, in severe cases, intravenously. The dosage and duration of zinc supplementation are individualized based on the severity of symptoms and response to treatment.

In addition to zinc supplementation, it is essential to address any associated complications. This may include the treatment of skin infections, nutritional support to correct deficiencies of other nutrients, and management of gastrointestinal symptoms such as diarrhea and vomiting.

In conclusion, acrodermatitis enteropathica is a rare genetic disorder characterized by impaired zinc absorption and resulting in zinc deficiency. It presents with a triad of symptoms involving the skin, gastrointestinal system, and immune system. Early diagnosis and lifelong zinc supplementation are crucial in the management of this condition to prevent complications and improve overall health outcomes for affected individuals.

 

 

Written by:

Deemah AlHuraish, Medical Student.

Revised by:

Maee Barakeh, Medical Student.

 

References:

DermNet.

NCBI.

Bolognia Textbook of Dermatology.

Benign Familial Pemphigus: Hailey–Hailey Disease

 Benign familial pemphigus, known as Hailey–Hailey disease, is an autoimmune uncommon hereditary blistering skin condition. This condition is unrelated to pemphigus vulgaris and has a different outcome.  Although it can happen at any age, benign familial pemphigus often manifests in the second to fourth decade. After that, it usually lasts a lifetime. All races are equally affected.

Etiology:

Although isolated occurrences of benign familial pemphigus without a family history can occasionally occur, the condition is hereditary usually. The ATP2C1 gene, which is located on chromosome 3q21–24, has now been confirmed to be defective. The calcium and manganese pump protein SPCA1 (Secretory Pathway Calcium/manganese-ATPase) is encoded by this gene. Desmosomes, which hold the keratinocytes together, appear to assemble improperly in the absence of enough calcium. The skin cells in benign familial pemphigus unstick from one another due to the genetic abnormality.

Clinical features:

In the skin folds, the disease often starts as a symmetrical, painful, erosive, and crusty skin rash. The armpits, groins, neck, under the breasts, and in between the buttocks are typical locations. The lesions usually fade away without leaving any scars. As the lesions get bigger, the center clears leaving a typical ring shape. If the lesions persist for a while, they could thicken. After that, the skin tends to macerate, producing painful cracks. These symptoms are exacerbated by heat, sweating, and friction. 

Diagnosis:

Benign familial pemphigus is often diagnosed based on appearance and family history, however, it is frequently confused with other skin conditions. Other blistering disorders, tinea cruris, thrush, and impetigo appear similarly. A skin biopsy may be needed for diagnosis. The histology is typical, with layers of detachment from the skin cells (acantholysis) lining up like a row of tombstones. The immunofluorescence test for antibodies comes out negative, in contrast to pemphigus vulgaris. Family members cannot yet access any diagnostic tests.

Management:

There is no definitive cure for this disease. Treatment is aimed at reducing symptoms and preventing flares. It is divided into topical and oral medication, in addition to general advice and other treatments. 

General advice includes avoiding triggers, washing, and drying skin folds carefully, and soft and loose clothing. Topical prescriptions include corticosteroids, antibiotics, benzoyl peroxide, ketoconazole, calcipotriol cream, and topical calcineurin inhibitors. Oral prescriptions include antibiotics, antivirals if herpes virus infection is a recurrent issue, and anticholinergic medications to reduce hyperhidrosis. In extreme circumstances, carbon dioxide laser vaporization or dermabrasion produces healing scars that are resistant to recurrence.

Complications: 

Secondary bacterial infection produces an unpleasant scent, also herpes simplex can cause blisters to form, and it has the potential to develop into a very painful viral illness (eczema herpeticum).

Prognosis: 

Many patients have long remissions, and an improvement with age does occur.

Written by:

Mohammed Alahmadi, medical student. 

Revised by:

Maee Barakeh, medical student.

References:

DermNet

Fitzpatrick’s Color Atlas and Synopsis of Clinical Dermatology

Review of Dermatology by Ali Alikhan

PAPA Syndrome

PAPA syndrome, also known as Pyogenic Arthritis, Pyoderma Gangrenosum, and Acne syndrome, is a rare autoinflammatory disorder characterized by a triad of symptoms: pyogenic arthritis, pyoderma gangrenosum, and severe acne. 

Pathophysiology:

The exact pathophysiology of PAPA syndrome is not yet fully understood. However, it is believed to be an autosomal dominant disorder caused by mutations in the PSTPIP1 gene, which is involved in regulating the immune system and inflammatory responses. The mutations lead to dysregulated production of pro-inflammatory cytokines, primarily interleukin-1 beta (IL-1β), resulting in chronic inflammation and tissue damage.

Clinical and Distinctive Features:

PAPA syndrome typically manifests in childhood or adolescence, although adult-onset cases have also been reported. The clinical features of PAPA syndrome include:

  1. Pyogenic Arthritis: Recurrent episodes of painful joint inflammation, particularly affecting large joints such as the knees, hips, and ankles. These episodes are characterized by swelling, warmth, and limited range of motion.
  1. Pyoderma Gangrenosum: Painful skin ulcers that develop in various areas of the body, most commonly on the lower extremities. These ulcers begin as pustules and progress to deep, necrotic wounds with undermined borders.
  1. Severe Acne: Persistent and severe acne, nodulocystic type, that is resistant to conventional treatments. It often involves the face, chest, and back, and can lead to scarring.

Diagnosis:

Diagnosing PAPA syndrome can be challenging due to its rarity and overlapping symptoms with other conditions. However, a comprehensive evaluation including a detailed medical history, physical examination, and laboratory tests can aid in the diagnosis. Key diagnostic criteria include the presence of the characteristic triad of symptoms and genetic testing to identify mutations in the PSTPIP1 gene.

Management:

The management of PAPA syndrome focuses on controlling symptoms, reducing inflammation, and preventing complications. Also, it involves a variety of approaches depending on the dominant manifestation:

Arthritis:

– Arthritis episodes often respond well to oral or intra-articular corticosteroids.

– In cases where corticosteroids are not satisfactory or arthritis recurs frequently, long-term corticosteroid use may be necessary, despite potential side effects.

Pyoderma Gangrenosum:

– Pyoderma gangrenosum may show some response to oral corticosteroids.

– Local immunosuppressant and anti-inflammatory drugs in the form of creams are commonly used.

– Treatment response is usually slow, but new biologic drugs targeting IL-1 or TNF have demonstrated efficacy in individual cases.

Acne:

– Acne treatment in PAPA syndrome may involve oral tetracycline antibiotics or isotretinoin, depending on the severity of the condition.

Developments in Treatment:

– Biological response modifiers, which target inflammatory proteins (cytokines), have shown success in managing other inflammatory conditions and are being explored for PAPA syndrome.

– Treatments targeting tumor necrosis factor (TNF) such as infliximab, etanercept, and adalimumab, as well as those targeting interleukin 1 (anakinra), have shown positive responses in cases of resistant arthritis and pyoderma gangrenosum.

Written by:

Deemah AlHuraish, medical student.

Revised by:

Maee Barakeh, medical student.

References:

DermNet

NCBI

Rosacea

Rosacea is a chronic skin disease that affects the central face and manifests with a variety of cutaneous or ocular symptoms.

Epidemiology:

Rosacea is primarily found among adults over 30 years old, and females are more likely to develop the disorder than males. People with light pigmentation or skin phototypes I and II are thought to be more prone to rosacea than those with darker pigmentation or skin phototypes III and IV.

Pathogenesis:

Rosacea has a poorly understood pathogenesis. Several potential contributing factors have been identified, including abnormalities in the innate immune system, inflammatory reactions to cutaneous microorganisms such as Demodex folliculorum and Staphylococcus epidermidis increased density on the skin , ultraviolet radiation exposure, vascular hyperreactivity, and genetics.

Clinical features:

Rosacea can be divided into four different types:

Type 1 – Erythematotelangiectatic Rosacea: Characterized by flushing and persistent central facial erythema with or without telangiectasia.

Type 2 – Papulopustular Rosacea: Characterized by persistent central facial erythema with transient papules and/or pustules.

Type 3 – Phymatous rosacea: Characterized by thickened skin with irregular surface and nodularities, particularly on the nose, chin or ears.

Type 4 – Ocular rosacea: Characterized by inflammations of the eyes and eyelids causing burning, stinging, dryness, and foreign body sensation of the eye.

Rosacea flares are usually associated with common triggers including sunlight, heat, stress, alcohol, and spicy foods.

Diagnosis:

For most patients, clinical assessment suffices to diagnose rosacea and rule out other disorders that might resemble it. The use of skin biopsies is rarely recommended, but can be beneficial if another disorder with specific histopathologic findings is suspected, or if granulomatous rosacea is suspected.

With highly pigmented skin, centrofacial erythema and telangiectasias can be subtle. A careful examination of other features of rosacea together with techniques such as dermoscopy and diascopy may help diagnose rosacea in patients with highly pigmented skin.

Management:

 Patient with rosacea should be instructed on the avoidance of triggers, gentle skin care routine including frequent moisturizing, avoiding exfoliant, and sunscreen use. 

Persistent erythema could be managed with brimonidine. Additionally, laser therapy or intense pulsed light can be used for facial erythema as well as facial telangiectasia.

Treatment with topical metronidazole, azelaic acid, or ivermectin is recommended for mild papules and pustules. Moderate to severe diseases or mild diseases that do not respond to topical agents should be treated with oral tetracycline, doxycycline, or minocycline. Treatment with oral isotretinoin may benefit patients with papules and pustules that are resistant to other therapies.

Rosacea can damage the ocular tissues when ocular involvement occurs. An ophthalmologist should be consulted if signs or symptoms of ocular involvement are present.

Written by:

Ghaida Altammami, medical student

Revised by:

Maee Barakeh, medical student

References:

UTD

DermNet

Bolognia textbook of dermatology

Fox-Fordyce Disease: The Sweat Retention Disease

Fox-Fordyce disease, also called apocrine miliaria, is a chronic rare condition where the apocrine sweat is retained and causes inflammation. Post-pubertal women between the ages of 13 and 35 are most commonly affected. Males and children can sometimes be affected. 

Etiology and pathophysiology:

There is no known cause of Fox-Fordyce disease. In the hair follicle, a keratotic block traps apocrine perspiration. The epidermis’s apocrine sweat ducts burst and leak, resulting in swelling and agonizing itching. There are several factors recognized for the development of this disease including alteration of sweat components, emotional and hormonal influences, and laser hair removal. Heat, humidity, friction, and stress are common environmental factors that contribute to the disorder.

Clinical features:

Apocrine sweat glands are exclusively located in the axilla, pubic region, and around the nipples, hence Fox-Fordyce disease is distinguished by itching lumps around the hair follicles in these places. The following clinical findings are often found with this disease includes bilateral dome-shaped flesh-coloured to small reddish papules affecting hair follicles, secondary skin lesion due to starching (lichenification), and reduced or absent sweating in the affected region. Loss of hair in the affected area is frequently observed. 

Diagnosis:

The diagnosis of Fox-Fordyce disease is typically made clinically; dermoscopy features include central hyperkeratotic plug in each papule, multiple light brown to dark structureless areas, lack of pigment network, and folliculocentric papule. 

Skin biopsy results show keratotic plug, spongiosis and vesicle formation, perifollicular infiltrate of chronic inflammatory cells, and xanthomatous foamy cells.

Management:

There is no definitive cure for this disease. One of the first treatments used is frequently topical and intralesional corticosteroids. Topical calcineurin inhibitors might lessen itching and make skin lesions look better. Topical tretinoin has been demonstrated to lessen pruritus but has little impact on how the condition manifests clinically and may irritate. Clindamycin lotion applied twice daily could also help to lessen symptoms. While some individuals have short relief from oral isotretinoin, some women respond to oral contraceptives.  Phototherapy, electrocautery, and periareolar skin excision are examples of physical therapies that could be helpful.

Prognosis: 

Fox-Fordyce disease could linger for a long time. It may occasionally go away during pregnancy. Others may experience a menopausal resolution or a continuing problem.

 

Written by:

Mohammed Alahmadi, medical Student. 

Revised by:

Maee Barakeh, medical student.

References:

DermNet

Bolognia Textbook of Dermatology

Fitzpatrick’s Color Atlas and Synopsis of Clinical Dermatology

Hidradenitis Suppurativa (HS)



Hidradenitis Suppurativa (HS), also known as acne inversa, is a chronic inflammatory skin condition that primarily affects specific areas of the body such as the axillae, groin, perianal, perineal, and inframammary locations. It is characterized by persistent or recurrent boil-like nodules and abscesses that culminate in a purulent discharge, sinuses, and scarring.

 

Etiology and Pathophysiology

Hidradenitis suppurativa (HS) is a complex skin condition with multiple causes. It is influenced by genetic, environmental, and behavioral factors. Genetic factors include a mutation in the gamma-secretase Notch signaling pathway found in some affected families. Environmental factors like obesity and smoking, as well as hormonal influences, contribute to the development of HS. The condition involves blockage of hair follicles, abnormal skin bacteria, inflammation, and damage to glands and ducts. The exact cause of HS is unknown, but it is likely a combination of genetic predisposition, hormonal changes, immune system dysfunction, and external factors that contribute to its development and severity.

 

Distinctive Features

HS typically manifests as painful nodules or boils in the affected areas, progressing to form abscesses and interconnected sinus tracts. These lesions have a tendency to recur and can persist for weeks or even months, resulting in the formation of scars and thickening of the skin. HS significantly impacts a person’s quality of life, causing persistent pain, discomfort, and emotional distress.
Clinically, HS is characterized by a range of specific features, including open double-headed comedones, painful firm papules and nodules, pustules, fluctuant pseudocysts, and abscesses. Additionally, the disease is marked by draining sinuses that link the inflammatory lesions, and it can lead to the development of hypertrophic and atrophic scars.

Diagnosis

Diagnosing HS can be challenging due to its variable presentation and similarities to other skin conditions. Clinical diagnosis requires recognition of the morphology (deep, inflamed, painful nodules, sinus tracts, scars), the location (intertriginous areas, apocrine gland-containing areas), and the chronicity of the disease process (prolonged course with periods of activity and remission).

The Hurley staging system is commonly used to classify the severity of HS:
Stage I: Single or multiple abscesses without sinus tracts or scarring.
Stage II: Recurrent abscesses with sinus tracts and scarring in two or more areas.
Stage III: Multiple interconnected sinus tracts and abscesses involving larger areas, with significant scarring.

In some cases, additional tests, such as swabs to rule out infection or biopsies for histopathological examination, may be performed to confirm the diagnosis or exclude other conditions.

 

Management:

Treatment options for hidradenitis suppurativa (HS) encompass various approaches based on the severity of the condition. These include:

  1. Lifestyle Modifications: Patients are advised to maintain good hygiene, avoid tight-fitting clothing, quit smoking, and manage weight if overweight or obese. These lifestyle modifications can help reduce friction, sweating, and inflammation in the affected areas.
  2. Topical Treatments: In milder cases, topical treatments such as antibacterial washes, topical antibiotics (e.g., clindamycin phosphate 1% with benzoyl peroxide), and anti-inflammatory creams can be effective. These interventions aim to reduce bacterial colonization and inflammation.
  3. Systemic Medications: For moderate to severe HS, systemic medications may be prescribed. Antibiotics like tetracycline or clindamycin can be administered to suppress bacterial growth. Anti-androgen medications like spironolactone may be considered for women with hormonal influences. Biologic therapies, such as TNF-alpha inhibitors like adalimumab, have shown promise in reducing inflammation and disease activity.
  4. Surgical Interventions: In cases where medical therapy proves insufficient, surgical interventions may be necessary. These can include incision and drainage of abscesses, excision of affected tissue, and laser therapy to manage persistent or recurrent lesions.

 

Written by

Deemah AlHuraish, medical student

Revised by

Maee Barakeh, medical student

References

DermNet

NCBI