Postinflammatory Hyperpigmentation (PIH)

/in , /by

Postinflammatory hyperpigmentation (PIH), also called acquired melanosis, is an acquired transient pigmentation following inflammatory conditions, skin damage, or therapeutic interventions. Darker skin types seem to experience it the most. PIH occurs with equal incidence in males and females of all ages.

Pathophysiology

Dermal melanosis occurs when inflammation disrupts the basal cell layer, causing melanin pigment to be released and subsequently trapped by macrophages in the papillary dermis. On the other hand, arachidonic acid is released during the epidermal inflammatory response, where it is oxidized to produce prostaglandins, leukotrienes, and other substances. These inflammatory byproducts affect melanocyte and immune cell function. These inflammatory substances specifically activate epidermal melanocytes, leading them to enhance melanin synthesis and subsequently increase pigment transfer to neighboring keratinocytes.

Causes

When PIH causes inflammation in the epidermis, melanocytes are stimulated to produce more melanin and transfer it to nearby keratinocytes. Acne excoriée, lichen planus, systemic lupus erythematosus, chronic dermatitis, and cutaneous T-cell lymphoma, particularly erythrodermic variations, are examples of common inflammatory illnesses that lead to PIH. A few drugs may also contribute to PIH. These include tetracycline, chemotherapeutic treatments like bleomycin, 5-fluorouracil, and busulfan, as well as antimalarial medications.

Clinical features

PIH presents at the original insult site after it has healed. The lesions’ coloring ranges from pale brown to black. If the patches are exposed to sunlight, they could get darker.

Diagnosis

The diagnosis of PIH is typically made clinically; no particular testing is necessary. Dermal PIH and epidermal PIH can be distinguished using a Wood lamp examination. To rule out additional underlying causes of hyperpigmentation, a skin biopsy is necessary. Melanin can be localized in the epidermis and/or dermis by staining the biopsy samples with Fontana-Masson silver stain.

Management

Treatment for PIH is frequently a challenging and lengthy process that frequently takes 6 to 12 months to produce the necessary depigmentation. Topical treatment for PIH aims to bleach the lesion and includes hydroquinone, azelaic acid, vitamin C cream, tretinoin, corticosteroids, glycolic acid, kojic acid, arbutin, and licorice extracts. Physical treatment for PIH includes chemical peels, laser treatments, and intense pulsed light therapies. If pigmentation affects an exposed site, daily application of broad-spectrum SPF sunscreen is important.

Prognosis

Without therapy, the clinical symptoms of epidermal melanosis could take months or even years to go away. People with dark complexion may experience PIH for a longer period of time than people with light skin. UV exposure and ongoing or recurrent inflammation can exacerbate the condition.

Written by

Mohammed Alahmadi, medical Student

Revised by

Maee Barakeh, medical student

References

DermNet

Medscape

UpToDate

Melasma

/in , /by

Background 

Melasma is a skin pigmentation disorder, characterized by hyperpigmentation of the skin due to hyperfunctioning melanocytes. It affects the sun-exposed areas of the face, such as the centrofacial, malar, and mandibular regions. It is most prevalent among young to middle-aged women.

Etiology

According to some theories, melasma can be attributed to UV irradiation exposure as the melanocytes of involved skin will be hyperfunctional and will release larger amounts of melanin pigment compared to uninvolved skin. Another theory suggests that melasma may be caused by skin photoaging that affects genetically predisposed individuals.

Risk factors 

There are multiple factors that increase the risk of developing melasma. These factors include genetics, exposure to sunlight, skin type, and hormonal factors (including pregnancy, hormonal therapies, and oral contraceptives).

Clinical features

Melasma presents with light to dark brown or brown-grey patches with irregular borders which appear primarily on the face. Precisely, it affects the forehead, nose, cheeks, upper lip area, and chin in a symmetrical pattern

There are three common facial patterns of melasma distribution: 

1- Centrofacial melasma generally affects the forehead, cheeks, nose, upper lip, and chin

2- Malar melasma mainly affects the cheeks

3- Mandibular melasma affects the lower jawline. 

Extra facial melasma, which is less common than the facial melasma and usually difficult to treat, can occur on the arms, forearms, chest, or back of some patients.

Diagnosis 

Melasma is typically diagnosed clinically. The Wood’s lamp examination can be helpful in identifying the location of pigment (epidermal or dermal), especially in those with lighter complexions. Dermoscopy has become increasingly useful in diagnosing melasma and determining its level of pigment deposition. 

Management 

All patients with melasma should use a broad-spectrum sunscreen with an SPF of 50 or higher on a daily basis.

The first-line treatment regimen for mild melasma is hydroquinone 4% cream. Patients with mild to moderate melasma use fluocinolone, hydroquinone, and tretinoin triple combination creams (TCC), rather than hydroquinone 4% cream alone.

Chemical peels (glycolic acid, other alpha-hydroxy acids, salicylic acid, Jessner’s peel, and trichloroacetic acid) are other treatment options for patients with melasma who have failed to respond to topical skin lightening therapies. 

For patients with melasma who have not responded well to topical treatments and chemical peels, lasers and light therapies can be provided.

Written by

Ghida Altammami, medical student

Revised by

Maee Barakeh, medical student

References

Bolognia textbook of dermatology

DermNet

UTD

Albinism

/in , /by

Albinism is a genetic disorder characterized by the partial or complete absence of pigment (melanin) in the skin, hair, and eyes. It results from a group of inherited genetic mutations that affect the production or distribution of melanin.

 

Etiology and Pathophysiology

Albinism is primarily inherited in an autosomal recessive manner, meaning that both parents must carry a mutated gene for their child to be affected. These genes are involved in the production of melanin or the enzymes required for its synthesis. The specific genes involved vary depending on the type of albinism. The most common types include oculocutaneous albinism (OCA) and ocular albinism (OA).

In OCA, the melanin production is impaired in the skin, hair, and eyes. Mutations in genes such as TYR, OCA2, TYRP1, and SLC45A2 are commonly associated with different types of OCA. In contrast, OA primarily affects the eyes, and mutations in the GPR143 gene are usually responsible.

 

Distinctive Features and Clinical Presentation

The hallmark dermatological feature of albinism is the absence or reduction of melanin pigment in the skin. This results in a strikingly light complexion, characterized by a pale or milky-white appearance. The skin is highly susceptible to sunburn and damage from ultraviolet (UV) radiation due to the lack of protective melanin. Therefore, individuals with albinism must take extra precautions to protect their skin from sun exposure.

The lack of melanin in the eyes can result in various eye abnormalities, such as nystagmus (involuntary eye movements), strabismus (misalignment of the eyes), and photophobia (sensitivity to light). Reduced pigmentation in the iris may cause the irises to appear light blue, green, or gray.

In addition to photosensitivity, individuals with albinism may experience other dermatological manifestations. These can include freckle-like macules, which are small, well-defined, light brown spots that may appear on sun-exposed areas over time. The macules are not true freckles but rather an accumulation of melanin precursor molecules due to impaired melanin production.

 

Diagnosis

The diagnosis of albinism is typically made based on clinical examination, family history, and specialized tests to assess visual function. Genetic testing may be performed to confirm the specific type of albinism and identify the responsible gene mutations.

 

Management

Management of albinism primarily focuses on minimizing the complications associated with the condition. One of the significant complications associated with albinism is an increased risk of developing skin cancers, including melanoma. The absence of melanin, which acts as a natural protective barrier against UV radiation, makes the skin more vulnerable to the harmful effects of the sun. Therefore, individuals with albinism must adopt strict sun protection measures to minimize the risk of skin cancers. These measures include using broad-spectrum sunscreen with a high sun protection factor (SPF), wearing protective clothing that covers the skin, seeking shade during peak sun hours, and regularly examining the skin for any suspicious lesions.

Regular dermatological examinations are essential for early detection of skin cancers in individuals with albinism. Dermatologists can perform thorough skin examinations and educate patients about self-examination techniques. Any suspicious skin lesions should be promptly evaluated and, if necessary, biopsied for further assessment

Visual aids, such as prescription glasses, contact lenses, or low-vision aids, can help improve visual acuity and alleviate the symptoms of nystagmus and strabismus. Regular eye exams are crucial for monitoring and managing any ophthalmic complications.

Psychological support and counseling are essential for individuals with albinism, especially during childhood and adolescence, as they may experience social and psychological challenges due to their appearance and visual impairments. Educating family members, peers, and educators about albinism can foster understanding and support.

 

Written by:

Deemah AlHuraish, Medical Student.

References:

DermNet

Medscape

Vitiligo: A Comprehensive Overview

/in , /by


What is Vitiligo

Vitiligo is a chronic, acquired, depigmenting, autoimmune disorder of the skin, resulting in the progressive loss of pigment-producing cells (melanocytes) which affect the color of the skin and hair. It manifests as milky-white patches of the skin, especially in those with dark skin, and it can be quite disabling from a cosmetic standpoint.

Epidemiology of Vitiligo

0.5–2% of people in the population have vitiligo. Between 20 and 24 years old is the typical onset age. Both sexes are equally affected, and there is a constant incidence across all races.

Causes of Vitiligo

Vitiligo is a multifactorial disorder related to both genetic and non-genetic factors. While environmental factors account only for 20% of vitiligo risk, genetic factors seem to account for 80% of it. The pathogenic hypotheses for vitiligo are variable and complex. The autoimmune destruction of melanocytes hypothesis suggests that autoantibodies are directed against several melanocyte antigens such as tyrosinase and tyrosinase-related proteins 1 and 2 (TYRP1 and TYRP2), which are crucial enzyme in the synthesis of melanin.

Clinical Features of Vitiligo

In most cases, vitiligo develops slowly. The most typical manifestation is a total loss of pigment in one or more macules or patches of the skin, which are characterized by their unique milky white color. Also, it typically has well-defined convex borders with possible hyper- or hypopigmented, red, or unaffected skin color borders. Vitiligo can be found in any region of the body; however, it tends to be more prevalent in sites of specific trauma, such as a cut, burn or abrasion, which is known as the Koebner phenomenon.

Classification of Vitiligo

Vitiligo classification is confusing. The following classification divides vitiligo into four general types. First, non-segmental vitiligo which tends to be bilateral and symmetrical. Second, segmental vitiligo which is usually unilateral and does not cross the midline. Third, mixed vitiligo, and lastly, unclassified vitiligo. These four classes are further divided into many subtypes. 

Diagnosis of Vitiligo

The diagnosis of vitiligo is typically made clinically; no particular testing is necessary. However, there are numerous instruments, such as the wood’s lamp, dermoscopy, and skin biopsy, that assist in the diagnosis.

Management of Vitiligo

There is no cure for vitiligo. The aim of treatment is to stop the progression of the disease and to achieve a satisfactory repigmentation. Minimizing skin injury and sun protection are important measures to limit disease progression. Topical treatments are commonly used which include corticosteroids, calcineurin inhibitors, and in some cases, JAK inhibitors cream. Phototherapy is also widely used, options include narrowband UVB, psoralen photochemotherapy(PUVA) and excimer laser which is useful in localized lesions of vitiligo. Systemic treatment may be needed, including systemic steroids, methotrexate, ciclosporin, and mycophenolate mofetil. Additionally, depigmentation therapy may be used in widespread disease with only a few areas of normally pigmented skin. 

Outcome of Vitiligo

There are some predictors that suggest an active disease, including peripheral hypopigmentation, confetti-like depigmentation, ill rather than well-defined borders, and the Koebner phenomenon. 

Vitiligo’s clinical course is incredibly variable. Vitiligo typically grows slowly over several months, then goes dormant for years. It can be challenging to manage.

 

Written by

Mohammed Alahmadi, medical student. 

Revised by

Maee Barakeh, medical student

References

Medscape

DermNet

Bolognia textbook of dermatology

 

Trichotillomania

/in , /by

Background

Trichotillomania is a hair pulling disorder, manifested by an uncontrollable desire to pull out one’s hair resulting in hair loss. It is often associated with skin picking. According to estimates, trichotillomania affects around 4% of the population, and it is more common in females with a 9:1 ratio. The onset of this disorder is usually at its peak during early adolescence and during the pre-school years.

Etiology & Pathophysiology

The cause is still uncertain, but some genetic factors have been identified as possible contributors. The pathogenesis of this disease could be linked to structural abnormalities or brain’s neurotransmitter imbalance. Moreover, it has been found that trichotillomania is largely associated with obsessive-compulsive disorder. In addition, it is crucial to be aware that stress and anxiety can also contribute to trichotillomania as a coping mechanism for the individual.

Clinical features 

Various body sites can be affected by trichotillomania, including the scalp, face, arms, legs, and pubic region. The scalp, however, is the most common area for both children and adults. Due to the frequent pulling of hair at different times and at different sites over time, there is a noticeable variance in the length of the hair shafts. An individual’s pattern of hair loss can range from slightly thinning of the hair or unnoticeable hair loss patches to complete baldness.

Diagnosis

The diagnosis of trichotillomania is based upon history and physical examination.

According to the DSM-5, trichotillomania can be diagnosed as a disorder based on the following diagnostic criteria:

  • Hair loss caused by repeated hair pulling
  • Consistent attempts to stop or reduce hair pulling
  • At least one important area of functioning is significantly impaired by hair pulling
  • Hair pulls or hair loss are not associated with any other medical conditions
  • Hair pulling does not appear to be explained by another mental illness

It is essential to exclude other causes of hair loss before making a diagnosis. A skin biopsy can be performed in order to confirm the diagnosis and exclude any other causes of hair loss.

Management

The treatment should begin with reassurance and education of the parents and caregiver as well as the child. Patients are typically required to be seen by several different specialties, including primary care physicians, dermatologists, psychiatrists, and psychologists. Cognitive behavioral therapy (CBT) and habit reversal training have been found to be the most effective treatments for trichotillomania. Medications such as tricyclic antidepressants and selective serotonin reuptake inhibitors (SSRIs) may also be prescribed in resistant cases in adolescents and adults to manage symptoms.

Prognosis

Trichotillomania is typically benign and self-limited in children. An early diagnosis and treatment of the disorder improve the prognosis. In adolescents and adults, however, trichotillomania may be episodic, but tends to be chronic, making treatment more challenging.

Complications

There is a possibility that permanent hair loss may be one of the long-term complications of this disease. Moreover, an unusual but seriously dangerous complication of trichotillomania known as trichobezoar occurs when patients ingest pulled hair. There are also other complications that have been reported, such as skin infections, and blepharitis.

Written by

Ghida Altammami, medical student

Revised by

Maee Barakeh, medical student

References

National Library of Medicine

UpToDate

DermNet

Telogen and Anagen Effluvium: A Comprehensive Overview

/in , /by


Hair loss is a common problem that can have a significant impact on an individual’s quality of life. Telogen effluvium (TE) and anagen effluvium (AE) are two types of hair loss that can occur due to various factors. It is important to note that neither TE nor AE are scarring types of hair loss. In both conditions, the hair loss is typically temporary and the hair follicles are not permanently damaged. However, in rare cases, if the underlying cause is not identified and addressed, the hair loss may become permanent. In this article, we will discuss the etiology, pathophysiology, clinical features, presentation, diagnosis, management, prognosis, and complications of TE and AE.

Etiology

The etiology of TE and AE differs. TE can be triggered by a range of physical and emotional stressors, such as pregnancy, surgery, illness, or medications. In contrast, AE is usually caused by exposure to certain toxins, medications, or radiation therapy.

Pathophysiology

The pathophysiology of TE and AE is distinct. In TE, the hair follicles are prematurely pushed into the resting phase of the hair growth cycle (telogen phase), resulting in an increase in the number of hairs shed from the scalp. AE involves damage to hair follicles during the growing phase of the hair growth cycle (anagen phase), leading to sudden and widespread hair loss.

Clinical Features

The clinical features of TE and AE vary depending on the underlying cause. In TE, the hair loss is gradual and diffuse, and there is usually no noticeable thinning of the hairline. In contrast, AE is characterized by sudden hair loss, which may be accompanied by redness or itching of the scalp.

Presentation

The presentation of TE and AE also differs. In TE, hair loss is typically gradual and may occur over several months. Patients may notice an increase in shedding when brushing or washing their hair. In contrast, AE is characterized by sudden hair loss, which may occur within a few days or weeks. Patients may notice clumps of hair falling out when they brush or wash their hair.

Diagnosis

The diagnosis of TE and AE is usually made based on the patient’s history and physical examination. Blood tests may be ordered to rule out underlying medical conditions that could be causing the hair loss. A scalp biopsy although is rarely needed, it may also be performed to confirm the diagnosis.

Management

The management of TE and AE depends on the underlying cause. In many cases, the hair loss will resolve on its own once the underlying cause is identified and addressed. However, if the hair loss is causing significant distress, there are treatments available to help promote hair regrowth. These may include topical medications, oral medications, or hair transplant surgery.

Prognosis

The prognosis for TE and AE is generally good, as the hair loss is usually temporary and will resolve once the underlying cause is addressed. However, in some cases, the hair loss may be permanent.

Complications

Complications of TE and AE are rare but can occur if the underlying cause is not identified and addressed. In some cases, the hair loss may be permanent, leading to significant distress and decreased quality of life. Additionally, if the hair loss is caused by an underlying medical condition, there may be other health complications that need to be addressed. 

 

Written by

Deemah AlHuraish, medical student

Revised by

Maee Barakeh, medical student

References

UpToDate

DermNet

Androgenetic Alopecia (MPHL & FPHL)

/in , /by


Overview of Androgenetic Alopecia

Androgenetic alopecia is an androgen-dependent hereditary disorder characterized by the progressive transformation of terminal hairs into indeterminate hairs, and then vellus hairs. The inheritance is polygenic, with genetic input from either or both parents. It is a highly prevalent disease that affects both men and women, resulting in male pattern hair loss (MPHL) and female pattern hair loss (FPHL).

Etiology of MPHL

MPHL is the most prevalent form of diffuse hair thinning and baldness in adult males. It is caused by a genetically determined sensitivity to the effects of dihydrotestosterone (DHT), which is regulated by the enzyme 5-alpha reductase. DHT is thought to shorten the anagen (growth) phase of the hair cycle; together with the miniaturization of the follicles, resulting in progressively thinner and fewer hairs.

Presentation of MPHL

MPHL presentation patterns can be classified using the Norwood-Hamilton scale. It is characterized by frontoparietal and frontal hairline recession and vertex thinning, which then progresses into a bald patch on top of the head.

Treatment of MPHL

Minoxidil solution and finasteride tablets are FDA approved medications for the treatment of MPHL. Hair transplantation is a surgical option that is used for the treatment. Platelet-rich plasma injections and lesser therapy are alternative therapies under investigation. Finasteride has shown to be effective in managing MPHL. It works by blocking the enzyme type II 5a-reductase activity and reducing the production of DHT.

Etiology of FPHL

FPHL is a distinct type of diffuse female hair loss. It is presently unknown whether androgens play a role in FPHL, whereas their role in male pattern baldness is clear. The vast majority of women with FPHL have normal blood levels of androgens.

Presentation of FPHL

FPHL is characterized by diffuse central thinning of the crown with preservation of the frontal hairline. The severity of FPHL can be assessed using the Ludwig scale according to the central part width. FPHL is frequently confused with a condition known as chronic telogen effluvium, as both conditions cause excessive hair loss.

Treatment of FPHL

Minoxidil solution is approved for the management of FPHL. In cases with hyperandrogenemia, other medications that suppress androgen can be added, such as oral contraceptives, spironolactone, or finasteride. Hair transplantation can also be offered to women with severe FPHL.

Burden of Androgenetic Alopecia

Numerous studies have demonstrated that hair loss is not merely a cosmetic issue, but also a major source of emotional distress. Studies indicate that hair loss is associated with sentiments of low self-esteem, depression, introversion, and unattractiveness.

Written by

Mohammed Alahmadi, Medical Student

Revised by

Maee Barakeh, medical student

References

DermNet

Medscape

Bolognia textbook of dermatology

 

Alopecia Areata

/in , /by

Background

Alopecia areata is an autoimmune condition that causes the body to attack the hair follicles, resulting in hair loss. Typically, this condition is characterized by round patches of non-scarring hair loss; and occasionally, nails changes.
It is estimated that the lifetime risk of alopecia areata is approximately 2%. According to the data, 25 to 36 years of age seems to be the average age of onset.

Etiology

It has been hypothesized that the loss of immunity associated with anagen hair follicles plays a key role in the pathogenesis of this disease. Also, genetic factors are involved in disease susceptibility and severity.

Comorbidities

Alopecia areata was found to be associated with several comorbidities, including depression, anxiety, and other autoimmune diseases, such as thyroid disease, lupus erythematosus, vitiligo, psoriasis, rheumatoid arthritis, and inflammatory bowel disease.

Clinical features 

Alopecia areata may present in different patterns. Patchy alopecia areata is the most common pattern; it is characterized by well-circumscribed round/oval patches of hair loss with normal skin appearing. Other less common patterns include, alopecia totalis which presents as complete loss of scalp hair, and alopecia universalis which presents as complete loss of body hair.
The scalp is most commonly affected by this condition, but any other area that bears hair can also be affected. The involvement of nails is generally indicative of a more severe type of hair loss. Usually, this condition manifests itself within a short period of time and may progress to the point of hair loss.

Diagnosis

Typically, alopecia areata is diagnosed based on the clinical features of the condition. Additionally, there are several helpful tools that can help support the diagnosis, including dermatoscopes, hair pull tests, and skin biopsy. Dermoscopic findings of active disease include exclamation point hairs, broken hairs, yellow dots, and black dots.

Management

Alopecia areata has an unpredictable course and may improve on its own. There is a wide range of treatments that is available for the management of alopecia with varying degrees of success. Generally intralesional and topical corticosteroids are considered first-line treatment for most patients.
For mild cases, options include Intralesional corticosteroid injections, topical treatments with corticosteroids or minoxidil. For more advanced cases, topical immunotherapy is used.  Systemic therapies are reserved for severe or refractory diseases, including systemic glucocorticoids and immunosuppressants such as cyclosporine and methotrexate. The FDA has recently approved Baricitinib, which is a JAK inhibitor with promising outcomes for alopecia treatment.

Written by

Ghida Altammami, medical student

Revised by

Maee Barakeh, medical student

References

DermNet

National Library of Medicine

Bolognia textbook of dermatology

Netherton Syndrome

/in , /by

Netherton syndrome is a rare genetic disorder that affects the skin, hair, and immune system. It is caused by mutations in the SPINK5 gene, which provides instructions for making a protein called LEKTI. LEKTI plays a crucial role in regulating the activity of enzymes called serine proteases, which are involved in many biological processes, including the development and maintenance of the skin barrier.


Distinctive Features

Netherton syndrome is characterized by three distinctive features: ichthyosiform erythroderma, trichorrhexis invaginata, and atopic diathesis. Ichthyosiform erythroderma is a type of skin inflammation that causes red, scaly patches on the skin, particularly on the scalp, face, and trunk. The skin may be itchy and prone to infections. Trichorrhexis invaginata, also known as ‘bamboo hair’, is a hair shaft abnormality that causes short, brittle, and easily broken hair that looks like bamboo shoots under the microscope. Atopic diathesis is a predisposition to allergic diseases, such as atopic dermatitis, asthma, and food allergies.

 

Clinical Features

The symptoms of Netherton syndrome can vary in severity and presentation, even among individuals with the same genetic mutation. In addition to the distinctive features, affected individuals may also experience recurrent infections, failure to thrive, and developmental delays.

 

Diagnosis

Netherton syndrome can be diagnosed upon the presence of the skin lesions, hair findings, family history of Netherton syndrome, or finding of SPINK5 mutation by DNA sequencing. Genetic testing and a skin biopsy could be helpful in confirming the diagnosis.

 

Management

Treatment of Netherton syndrome is mainly supportive, and aims to manage the symptoms and complications of the condition. Topical emollients, such as creams or ointments that contain lipids and humectants, can help to moisturize and protect the skin and prevent itching and scratching. Antihistamines, corticosteroids, or topical calcineurin inhibitors may be used to alleviate inflammation or itching. In severe cases, Intravenous immunoglobulin (IVIG) replacement therapy has led to improvement in some patients.

 

Future Research

Research on Netherton syndrome is ongoing, and several potential therapies are being investigated. One promising approach is the use of recombinant LEKTI, which could restore the normal regulation of serine proteases in the skin and improve the skin barrier function. Other strategies involve the modulation of specific inflammatory pathways or the transplantation of healthy skin cells.


Written by

Deemah AlHuraish, Medical Student

References

UpToDate

DermNet

Piebaldism

/in , /by

What is piebaldism

Piebaldism is an uncommon inherited pigmentation disorder manifesting at birth with patchy leukoderma (white skin) and white hair (poliosis). Consequently, the most prominent trait of piebaldism is a white forelock (a patch of white hair immediately above the hairline). Piebaldism is an autosomal dominant genetic condition, so each offspring of an affected parent has a 50% chance of inheriting the disorder.

Epidemiology of piebaldism

The incidence of piebaldism is unknown but is estimated to range between 1:40,000 and 1:100,000. Both genders are affected equally. There is no difference in prevalence between ethnic groups, but the disorder is more noticeable and readily identifiable in people with darker skin tones.

Causes of piebaldism

75% of cases of piebaldism are due to mutations of the KIT proto-oncogene on chromosome 4; over 45 distinct point mutations, deletions, nucleotide splice mutations, and insertions of the KIT gene have been identified. The KIT gene mutation causes abnormal migration of melanoblasts from the embryonic neural crest to the epidermis, resulting in melanocyte-deficient skin patches.

Clinical features of piebaldism

White forelock, leukoderma of the central portion of the forehead, eyebrow and eyelash hair may also be affected, white patches of face, trunk, and extremities, and a narrow border of hyperpigmented skin surround the white unpigmented patches are the clinical characteristics of piebaldism. In the mild form, only small patches of leukoderma may be present, whereas in the severe form, the forelock is white and there are larger white patches on the trunk and extremities.

Diagnosis of piebaldism

Piebaldism is clinically diagnosed at birth or shortly thereafter. A leukoderma skin biopsy specimen will reveal the absence of melanocytes and melanin pigment. The diagnosis can be confirmed by genetic testing of a peripheral blood sample.

Management of piebaldism

The treatment begins with sun protection measures, solar avoidance during peak UV exposure hours, and self-examination of the skin to detect skin cancer. The surgical and procedural treatment consists of dermabrasion followed by melanocyte-enriched cell suspensions, melanocyte transplant, suction epidermal grafting, or full-thickness punch grafting. There may be a need for a combination of these methods, which can be enhanced by UV light therapy. Cosmetic camouflage techniques can conceal hair and skin pigmentation changes.

Complications of piebaldism

The complications of piebaldism include sunburn, skin cancers, and psychosocial consequences.

Written by

Mohammed Alahmadi, Medical Student.

References

DermNet

UpToDate

Melanoma

/in , /by


Overview & Epidemiology of Melanoma

Melanoma is a malignant tumor that arises due to the uncontrollable growth of melanocytes (pigmented cells). Melanoma is the fifth most common cancer among men and women in the United States. The superficial spreading melanoma is the most common subtype accounting for 55-60% of all melanomas. 


Risk factors of Melanoma

The exact cause of melanoma is unknown, however, some identified risk factors include family history, personal history of melanoma, basal cell or squamous cell carcinoma, sun exposure, pale complexion, immunosuppressive states, and having multiple moles or atypical navi. 

 

Clinical features of Melanoma

Patients may notice newly formed moles or changes in their pre-existing moles, which are often pruritic and easily bleeding. Melanoma development is not limited to sun-exposed areas, it can be found in any area of the body. 

 

Diagnosis of Melanoma

To diagnose melanoma, a detailed history and skin examination are required. A skin examination should evaluate whether a lesion shows one or more characteristics suggesting melanoma including the ABCDE (asymmetry, Irregular border, Color variations, Diameter greater than 6 mm, Elevated surface) assessment. Also, a comparison of individual nevus patterns and changes in preexisting lesions in size, color, or shape. It is necessary to perform a full-thickness biopsy for a definitive melanoma diagnosis.

 

Management of Melanoma

Melanoma at its early stage is often treated surgically by local excision combined with sentinel lymph node biopsy or elective node dissection. The treatment for advanced melanomas includes surgery, medical treatment, and radiation therapy.
If left untreated, melanoma can be life-threatening. It is estimated that 17% of patients develop metastatic disease. Early detection and treatment are essential for successful outcomes.

 

Prevention of Melanoma

There is no doubt that identifying and eliminating causes and risk factors for melanoma plays a crucial role in prevention. Sun protection, avoiding tanning beds, regular screenings, and early detection of skin changes are key components of preventing melanoma. Education and awareness about melanoma clinical features and risk factors are also vital for early diagnosis and successful treatment.

 

Written by

Ghida Altammami, medical student

References

Up to Date 

DermNet 

NCBI

Necrobiosis Lipoidica Diabeticorum

/in , /by

 

Epidemiology of NLD

Necrobiosis lipoidica diabeticorum (NLD) is a rare granulomatous skin disorder that has a female predominance, with an approximate ratio of  3:1. It has been linked to diabetes mellitus; as up to 65% of NLD patients have diabetes or prediabetes; however, only 0.03% of patients with diabetes have NLD. The control of blood glucose levels usually does not have a significant effect on the course of NLD. In spite of that, diabetic patients with NLD do appear to have a higher rate of diabetes-related complications compared to diabetic patients without NLD. 

Pathogenesis of NLD

The cause of NLD remains unknown. It is postulated that immunologically mediated vascular disease is the primary cause of the altered collagen seen in NLD. Other theories suggest that microangiopathic vessel changes seen in diabetic patients could contribute to the development of collagen degeneration and subsequent dermal inflammation.

Clinical features of NLD

NLD starts as red–brown papules that are typically multiple and symmetrical on both shins. Later, it progresses into yellow–brown, atrophic, telangiectatic plaques surrounded by raised, violaceous rims. Pretibial region is the typical anatomical site for NLD, and it is less commonly seen in other sites including upper extremities, face and scalp. NLD is typically asymptomatic; however, some patients report pruritus, dysesthesia or pain. 

Diagnosis of NLD

NLD is diagnosed clinically when typical. A biopsy specimen from the palpable inflammatory borders is used to confirm the diagnosis. The histopathology is characteristic; it shows granulomatous epithelioid histiocytes arranged in a palisaded fashion around destroyed collagen (necrobiosis). The inflammation extends throughout the dermis and into subcutaneous fat septae.

Management of NLD

No treatment for NLD has proven to be effective. However, intralesional corticosteroids injected into the active borders of established lesions can be used as first-line treatment to halt disease progression and extension into the surrounding normal skin. In extensive ulcerations that are refractory to medical treatment, surgical management and skin grafting can be considered. 

Complications of NLD

Ulceration is a common complication for NLD that is seen in 1/3 of the cases, usually preceded by a minor injury to an established patch. Secondary bacterial infection, delayed healing and squamous cell carcinoma have been reported to develop in ulcerated NLD.

Written by

Maee Barakeh, medical student

References

Bolognia textbook of dermatology

DermNet