📚 Question Bank

Poor prognostic factors for vitiligo:

• Positive family history (patient 2)
• Mucosal vitiligo (patient 1)
• Lesions over bony prominences
• Isomorphic Koebner's phenomenon (patient 5)
• Non-segmental vitiligo

Leucotrichia, longer duration, and higher age at onset do not correlate significantly with progression.

Non-segmental vitiligo is characterized by a bilateral and symmetrical distribution of depigmented macules.

Segmental vitiligo is characterized by macules in a linear or flag-like pattern of mosaicism with a dermatomal distribution.

The image shows cutaneous macular hypopigmented whorls, streaks, and patches, corresponding to the lines of Blaschko, suggestive of hypomelanosis of Ito.

It is a rare neuroectodermal disorder of pigmentation. It is associated with epilepsy and mental retardation. Extracutaneous findings include neurological, ophthalmological, and skeletal defects.

The given clinical scenario is suggestive of incontinentia pigmenti. It is a rare X-linked dominant disorder with multisystemic ectodermal dysplasia that is usually lethal in males and presents in females with skin lesions, teeth abnormalities, alopecia, nail dystrophy, and ocular and neurological findings.

The skin lesions evolve through the following characteristic stages:

• Vesicular
• Verrucous stage
• Hyperpigmented streaks and whorls
• Linear hypopigmentation

The presence of multiple polyps in the GI tract along with lentigines on the lips is suggestive

of Peutz-Jeghers-Touraine syndrome. Malignant transformation of hamartomatous polyps is rare.

It is an autosomal dominant disease. It is due to the mutation of the serine/threonine kinase gene

(STK11).

Typical cutaneous features include lentigines of the lips (early feature). Associated melanocytic macules of buccal mucosa and digits are common. Hamartomatous polyps are present mainly in the jejunum but can occur throughout the GI tract.

Patients require lifelong screening as they are at high risk for carcinomas of the breast, ovary, colon, and stomach.

Beta-blockers do not cause hyperpigmentation. Drugs causing hypermelanosis:

• Amiodarone
• Tetracyclines
• Chloroquine
• Clofazimine
• Phenytoin
• Cytotoxic drugs like busulfan, cyclophosphamide, bleomycin, etc.
• Psychotropic drugs (e.g., trifluoperazine, imipramine)

The given clinical history of fever and joint pain and the image showing hyperpigmented macules on nose (chik sign) is suggestive of Chikungunya.

Post-chikungunya pigmentation (PCP) most commonly affects the nose and cheeks. It often appears as the fever subsides and may persist for about 3-6 months.

PCP mimics melasma and may be misdiagnosed if proper history is not taken.

Another close differential is fixed drug eruptions (FDE). FDE is a type of delayed hypersensitivity reaction. It is characterized by well-defined brown, hyperpigmented plaques that may follow vesiculobullous lesions. They occur on lips, hands, legs, face, genitalia, and oral mucosa, and can cause a burning sensation.They usually present 30 min to 8 h after drug exposure and recur at the same location on re-exposure. NSAIDs, Paracetamol and Cotrimoxazole are the most common drugs causing FDE.

The image below shows FDE on upper lip area:

The recurrence of hyperpigmentation occurring at the same site with the use of the same drug is characteristic of fixed drug eruption.

Fixed drug eruption is one of the most common drug-induced exanthems. The acute erythematous and bullous stages of fixed eruption characteristically settle leaving residual slate-brown hyperpigmentation, especially in those with darker skin types. The genitalia and perianal area are often affected.

Option A: Drug hypersensitivity is an immune-mediated reaction to a drug of which symptoms ranging from mild to severe include rash, anaphylaxis, and serum sickness.

Option B: Postinflammatory hyperpigmentation (PIH) is an acquired hypermelanosis occurring after cutaneous inflammation or injury e.g., acne vulgaris, atopic dermatitis, and impetigo.

Option D: Drug-induced hypermelanosis is localized or generalized hyperpigmentation that can be caused by a wide range of medications and chemicals. eg. busulphan. It doesn't necessarily occur at the same site with the reintroduction of drugs.

The lady has bindi leukoderma, which is caused by para-tertiary butyl-phenol (PTBP). It is present in adhesive sticker bindi.

This is called contact leukoderma or chemical leukoderma in which the chemical increases sensitivity and induces apoptosis of the melanocytes in the area of contact.

There is also evidence that azo dyes, by virtue of structural similarity to tyrosine, can directly inhibit melanogenesis by competing with that amino acid for binding with the tyrosinase enzyme.

The image below shows synthetic leather-/rubber-related leucoderma.

Chemical leukoderma Bindi leukoderma

Synthetic leather, rubber slip pers, latex condoms, rubber gloves

Hair dye

Alta (red color like henna)

Causative chemicals

Para-tertiary butyl-phenol (P TBP)

Mono-benzyl ether of Hydroq uinone (MBH)-Rubber antiox idant

p-Phenylenediamine (PPD)

Crocein scarlet MOO and sol vent yellow 3 (azo dyes)

The image below shows Alta depigmentation.

The image below shows hair dye depigmentation.

Naevus of Ota is more commonly seen in females.

It is an extensive, bluish, patchy, dermal melanocytosis. A large number of elongated dendritic melanocytes can be seen scattered among collagen bundles mainly of the superficial dermis.

It affects the sclera and the skin adjacent to the eye. It is distributed along the first and the second branches of the trigeminal nerve.

Most lesions are present at birth or develop during the first year of life, increasing in size and number in subsequent years. Lesions are more common in Asians.

Pigment targeting Qswitched laser systems is the treatment of choice.

This Chinese patient has a unilateral blue-greyish hyperpigmented macule on his shoulder, which is suggestive of nevus of Ito.

It affects the acromioclavicular region and upper chest. It primarily occurs in Chinese and Japanese people.

It is rarer than nevus of Ota which affects facial skin and sclera. It is distinguished from the nevus of Ota by its location in the area innervated by the posterior supraclavicular and lateral cutaneous brachial nerves.

Complications of nevus of Ota include meningeal melanocytoma of the brain, and malignant melanoma involving the meninges, choroid, iris, or orbit. In some rare cases, cutaneous melanoma can develop.

Pigment targeting Qswitched laser systems is the treatment of choice.

Becker nevus is a large, pigmented hairy patch on the shoulder, chest, or back of young males.

Nevus spilus is a congenital nevus presenting as a lentiginous macule that develops into multiple macules in a speckled distribution (image below).

The patient has dark brown macules on her face, that increase on sunlight exposure. This is suggestive of freckles or ephelis, which are produced due to increased melanin production by melanocytes on exposure to UV rays (with a normal number of melanocytes).

It is transmitted in an autosomal dominant pattern. They are seen in a number of inherited and acquired disorders including xeroderma pigmentosum, neurofibromatosis, and progeria. Freckles

are common in type 1 and type 2 skin types of Fitzpatrick Classification. First-line treatment is the use of a high SPF sunscreen.

The given image suggests the most likely diagnosis to be compound naevus. It is characterized by a hyperpigmented papule surrounded by a symmetrical, lighter brown, macular area.

A compound naevus is a slightly raised, oval, or round papule with a symmetrical shape. This naevus is also pigmented, with shades of brown according to the patient’s skin color.

Based on the position of melanocyte aggregates, the acquired melanocytic naevi can be classified into:

• Junctional - melanocytes in the dermo-epidermal junction
• Compound - melanocytes in the dermo-epidermal junction and dermis
• Dermal - melanocytes in the dermis

The given image showing hyperpigmented lesion on shoulder associated with hypertrichosis is suggestive of Becker's naevus.

It is an epidermal melanocytic naevus with aggregation of melanocyte clusters in the epidermis. It is often hairy. The onset is around adolescence when there is an increased sensitivity to androgens especially in the distribution of outer arms, scapular area and chest.

A triad of features can be seen:

• Hyperpigmentation
• Hypertrichosis
• Acne

Option A: Mongolian spots are slate blue areas in the lumbosacral region that spontaneously regress before puberty.

Option B: Naevus of Ito is unilateral hyperpigmentation in the acromioclavicular distribution. It is not known to have hypertrichosis or acne.

Option C: Congenital melanocytic nevi are common moles that become raised and have a cerebriform appearance and can be hairy. They can occur anywhere. The onset is at birth or soon after birth

Nevus anemicus occurs due to increased sensitivity of local cutaneous blood vessels to catecholamines such as epinephrine (adrenaline) and norepinephrine (noradrenaline). This hypersensitivity results in persistent vasoconstriction leading to hypopigmentation. Hence, it is also known as a pharmacologic nevus.

It is a congenital, localized, cutaneous vascular anomaly presenting as a pale, irregularly shaped patch on otherwise normal skin. Histology and electron microscopic examination show no abnormality in melanocytes or melanization.

Rubbing the lesion

Diascopy at the border of the lesion

Nevus anemicus No change

The border between the lesio n and the normal skin disapp ears due to the blanching of t he normal skin

Nevus depigment osus

Lesion becomes re d

No change

Simple lentigo occurs due to an increase in melanocytes at the dermal-epidermal junction.

Simple lentigo or lentigo simplex is a light to dark-brown or black macule that does not fade away once it appears. They usually appear during childhood and increase in number until the age of 40. It is more common in individuals with red hair and fair skin.

The image shows lentigo simplex- hyperpigmentation is evident in the basal and squamous epidermal cells.

This pregnant lady has chloasma or a mask of pregnancy. In non-pregnant women, it is called melasma.

Chloasma is very common in the 3rd trimester of pregnancy and is most marked in brunettes.

It is due to increased levels of estrogen and progesterone, stimulating the activity of melanocytes. Histopathology shows no increase in number but hyper-functional melanocytes. It resolves on its own after pregnancy.

Melasma is the most common cause of chronic facial melanosis. It is manifested by hyperpigmented macules that become more pronounced after sun exposure. Hypermelanosis affects mainly the upper lip, the malar regions, forehead, and chin. It is more common in women between 20-40 years. It is frequently seen in women on oral contraceptives.

Wood's lamp examination is useful to differentiate the level of pigmentation and treatment response:

• Epidermal melasma- shows enhanced color contrast
• Dermal melasma- shows less color contrast (more resistant to treatment)
• Mixed melasma.

Melasma is more chronic and requires treatment with depigmenting agents like:

• Kligman's triple combination - topical hydroquinone + tretinoin + corticosteroid compound cream (first line)
• Hydroquinone (reduces tyrosinase activity)
• Kojic acid (tyrosinase inhibitor)
• Chemical peels

The given image is suggestive of giant congenital melanocytic naevus or bathing trunk naevus. It has an increased malignant potential.

It is a very rare condition present in 1:20,000 births. This lesion is usually brown to black in color with a rough, warty, rugose, or cerebriform surface. To classify it as giant naevi, it should be gt;20cm in size. Coarse hairs can develop on it in due course.

These naevi are associated with leptomeningeal melanocytosis or neurofibromatosis.

Surgical excision is the mainstay of treatment and a cultured epidermal autograft is used to cover large postoperative surface area defects.

The image shows a child with a well-circumscribed, black, heterogenous lesion covered with hair. This is characteristic of a congenital melanocytic nevus (CMN). They may be present at birth or develop shortly thereafter. They are benign and can be brown, black, purplish, or red, and are usually a palpable lesion.

They can be classified based on size: small (lt;1.5 cm), medium (1.5-19.9 cm), and large or giant

(gt;20 cm). Larger CMN have a higher risk of developing malignant melanoma.

Management of CMN depends on the size and location of the lesion. Smaller nevi may be observed, while larger nevi or those at a higher risk for complications may require surgical excision, particularly if there is a concern for malignant transformation.

Complications of CMN include neurological abnormalities (intraparenchymal melanosis is the commonest finding), malignant melanoma, and other tumors like rhabdomyosarcoma.

The images below show different melanotic skin lesions:

The given image shows Mongolian spots. The coloration is due to the arrested migration of melanocytes within the deep dermis and to the epidermis. It is not due to increased melanocytes.

These are congenital macular areas of bluegrey pigmentation of varying size and shape located on the lumbosacral area in normal infants. The lesion develops in-utero, increases during infancy, and then diminishes. Sometimes may occasionally persist into adult life.

These are associated with Down syndrome and congenital hemangioma. Extensive Mongolian spots have been associated with Hurler syndrome and GM1 gangliosidosis type 1.

Hyperthyroidism may cause generalized hyperpigmentation, not hypothyroidism.

Generalized hypermelanosis or hyperpigmentation can be due to a variety of systemic diseases. A few common diseases are mentioned below:

• Addison's disease
• Cushing disease
• Hyperthyroidism
• Solid malignant tumor
• Pheochromocytoma
• Systemic sclerosis
• Renal Failure
• Hemochromatosis
• Folate and vitamin B12 deficiency
• Vitamin A deficiency
• Pellagra

The above image showing erythematous, scaly lesions having a flexural distribution with the given scenario is suggestive of eczema.

Eczema is inflammation of the skin seen in a variety of skin conditions

Spongiosis is the characteristic histopathological feature of acute eczema. It refers to intercellular epidermal edema that leads to stretching and rupture of the intercellular attachments, with the formation of vesicles.

Eczema is inflammation of the skin seen in a variety of skin conditions. Dermatitis is used to include all types of cutaneous inflammation so:

'All eczema is dermatitis, but not all dermatitis is eczema' Aetiologically, eczema may be classified as:

The hallmark symptom of eczema is intense pruritus. Other findings are:

Endogenous Atopic eczema

Asteatotic ecze ma

Venous eczema

Exogenous

Allergic contact eczem a

Irritant eczema

Post-traumatic eczema

Acute eczema

Vesicular eruptio n

Exudative Edematous

Chronic eczema

Erythema and scali ng

Excoriation Lichenification

The image below shows eczema.

The above scenario is suggestive of nummular dermatitis or nummular eczema.

The diagnostic lesion of nummular dermatitis is a well-demarcated coin-shaped erythematous plaque with vesicles surrounding it. Later central clearing (resolution) and peripheral extension lead to annular or ring-shaped lesions. Initially, it is red and pruritic but later, it becomes more scaly and less exudative.

Common locations involved are:

• Trunk
• Extensor surfaces of extremities:
• Men - Pretibial areas
• Women - Dorsal aspects of hand

The image below shows nummular dermatitis. Note the typical shape and demarcation of the lesion.

The above scenario of a hypopigmented, scaly patch is suggestive of pityriasis alba.

It is a pattern of dermatitis in which hypopigmentation is the most conspicuous feature. It is seen in the age group of 3-16 years.

Lesions have scaling and are usually not well marginated. In children, the lesions are often confined to the face and are most common on the cheeks and around the mouth and chin.

It is often a manifestation of atopic eczema but it is not confined to atopic individuals.

Option A: In leprosy, the hypopigmented patch is often associated with atrophy, loss of sensation, and loss of sweating. The lesion is not scaly.

Option B: In pityriasis versicolor the hypopigmented macules are perifollicular in

distribution. Fine, powdery branny scaling is present. Scratch sign positive. No relation to atopy. Option D: Atopic eczema is characterized by itchy papules, hypopigmentation is not a feature.

The clinical scenario depicting pruritic lesions at a flexural site along with a family history of atopy (asthma) is suggestive of atopic dermatitis (AD) or atopic eczema (AE). The scratch marks and excoriations shown in the image are due to pruritis, which is the hallmark feature of AD.

AD is a chronic relapsing inflammatory condition. It presents with erythematous macules, papules and vesicles that often start in early childhood, usually less than 2 years old. The lesions later become excoriated and lichenified. It is frequently associated with dryness of the skin

and secondary infections. In infancy, the lesions initially appear on face (sparing the napkin area) and later on extensor aspect of knees and elbows as the child starts crawling. In later childhood and in adults, the principal site of involvement is flexures.

The filaggrin monomers in keratinocytes in the epidermis bind and aggregate keratin bundles and intermediate filaments to form the epidermal barrier. Any damage/dysfunction of this barrier is associated with an increased risk of developing AD. Damage to this barrier can be due to environmental factors (detergents, hard water, UV light) or local inflammatory

reactions. Dysfunction of the barrier can be due to genetic mutation of the FLG gene leading to reduced filaggrin production or local immunomodulatory effects leading to reduced filaggrin expression.

Other options:

Option A: Seborrheic dermatitis is a chronic inflammatory skin condition characterized by erythema, pruritus, scaling, flaking, or crusting of the skin. It is often associated with Malasezzia fungal infection. A milder form of seborrheic dermatitis of the scalp is commonly known as dandruff.

Option C: Allergic contact dermatitis (ACD) is an inflammatory condition caused due to a delayed hypersensitivity reaction (Type 4 hypersensitivity) to a specific allergen that comes into direct contact with the skin.Patients usually present with pruritus, erythema, swelling,

papules, and papulovesicles. Some common allergens include nickel (found in artificial jewelry), PPD/Para phenylene diamine (in hair dye), chromate (in cement), rubber or latex, cosmetics, etc. Patch test (image below) is used for the diagnosis of ACD.

Option D: Erysipelas is a bacterial skin infection caused by Streptococcus pyogenes (Group A Streptococcus) characterized by raised, erythematous sharply demarcated rapidly spreading skin lesions, along with systemic symptoms like fever and chills. The skin may also have a peau d'orange or orange peel-like appearance.