Pigmentary Disorders Practice Questions

Q: The image shows presence of:

Nevus of Ota. - ***Nevus of Ota*** - The image exhibits a characteristic **blue-grey or brownish discoloration** on the face, specifically around the eye (periorbital region) and extending to the temple and cheek. - The presence of **scleral pigmentation** (blue discoloration of the sclera) is a classic finding associated with Nevus of Ota, due to dermal melanocytosis affecting both skin and ocular structures. - *Nevus spilus* - This condition presents as a **light brown patch** with speckles of darker macules or papules within it, resembling "spots on a spot." - It does not typically involve the deep blue-grey coloration or ocular pigmentation seen in the image. - *Giant melanocytic nevus of face* - While also a melanocytic nevus, a giant congenital melanocytic nevus is typically much larger, often covering extensive body areas, and has a more **uniform dark brown to black coloration** with a rugose or hairy surface, differing from the blue-grey hue and distribution shown. - Though it can occur on the face, the overall appearance, particularly the distinct blue-grey color and scleral involvement, is not typical for a giant melanocytic nevus. - *Port wine stain* - A port wine stain is a type of **capillary malformation** characterized by a flat, pink to red vascular lesion that darkens with age to a deep purple. - It blanches under pressure and is due to dilated capillaries, not melanin deposition, and does not cause the blue-grey pigmentation or scleral involvement seen here.

Q: A 24-year-old male presents with a lesion at the site shown in the image for 4 years. He says it has increased in thickness over the years. Diagnosis is:

Becker's nevus. ***Becker's nevus*** - This lesion typically presents as a **unilateral, hyperpigmented patch** that often appears during childhood or adolescence, increasing in size and thickness with associated **hypertrichosis** (increased hair growth). The image shows a large, irregularly shaped, hyperpigmented area on the torso of a young male, consistent with this description. - The history of increasing thickness over four years further supports **Becker's nevus**, as it is known to progress in thickness and texture, often becoming more indurated and sometimes verrucous. *Spitz nevus* - Spitz nevus is a benign melanocytic nevus typically presenting as a **pink or red, dome-shaped papule or nodule**, commonly on the face or limbs. - It rapidly grows but does not typically present as a large, hyperpigmented patch with associated hypertrichosis like the lesion shown. *Hyper-melanosis of Ito* - Hypermelanosis of Ito (also known as incontinentia pigmenti achromians) is characterized by **streaky or whorled hypopigmented (lighter) skin lesions**, often present at birth or in early infancy. - The image clearly shows a **hyperpigmented (darker) lesion**, which directly contradicts the characteristic hypopigmentation of hypermelanosis of Ito. *Congenital melanocytic nevus* - Congenital melanocytic nevi are typically present **at birth** or become apparent shortly thereafter. While they can be large and hyperpigmented, they usually do not have the prominent feature of increasing thickness and hypertrichosis developing many years later in adolescence or early adulthood in the same way as Becker's nevus. - The description of a lesion appearing during adolescence and increasing in thickness and hairiness for four years makes Becker's nevus a more specific diagnosis than a general congenital melanocytic nevus.

Q: A patient presents with the skin finding shown in the image. Identify the most likely diagnosis for this lesion.

Piebaldism. ***Piebaldism*** - The image shows a **localized patch of depigmentation** on the forehead, characteristic of **piebaldism**. - **Piebaldism** is a rare, congenital autosomal dominant disorder caused by a defect in melanocyte development and migration, resulting in stable, well-demarcated depigmented areas, often with a **white forelock**. *Vitiligo* - **Vitiligo** typically presents as **progressive, acquired macules and patches of depigmentation** that often enlarge over time. - While it can appear on the face, the sharply demarcated, congenital appearance seen here is more consistent with piebaldism. *Contact leukoderma* - **Contact leukoderma** is an **acquired depigmentation** resulting from exposure to chemicals (e.g., rubber, phenols). - It would usually present in areas of direct contact, and the congenital nature of the lesion in the image rules this out. *Albinism* - **Albinism** is a **generalized hypopigmentation** affecting the skin, hair, and eyes due to a defect in melanin production. - The image shows a localized patch of depigmentation, not a widespread lack of pigment characteristic of albinism.

Q: The clinical diagnosis is?

Albinism. ***Albinism*** - The image shows a child with characteristic features of **oculocutaneous albinism**, including **very pale skin**, light hair, and vivid red eyes due to the absence of melanin in the iris, allowing visibility of retinal blood vessels. - Albinism is a genetic condition resulting from a deficit in **melanin production**, affecting pigmentation of the skin, hair, and eyes. *Wilson disease* - Wilson disease is a genetic copper metabolism disorder affecting primarily the **liver, brain, eyes, and other organs**. - Clinical signs include **Kayser-Fleischer rings** in the cornea (copper deposits), liver disease, and neurological symptoms, none of which are consistent with the image. *Menke's disease* - Menkes disease is a rare X-linked recessive disorder of **copper transport**, leading to copper deficiency in the brain and other tissues. - It presents with severe neurological degeneration, **"steely" or "kinky" hair**, and connective tissue abnormalities, not the pigmentation issues seen in the image. *Waardenburg syndrome* - Waardenburg syndrome is a genetic disorder characterized by **hearing loss**, changes in hair and skin pigmentation (e.g., a white forelock), and distinctive facial features like widely spaced inner canthi. - While it involves pigmentation changes, it does not typically present with the generalized lack of pigmentation and **red-eye appearance** as strikingly as seen in albinism.

Q: The image shows Bilateral Xanthelasma palpebrarum. Which of the following is the most common type of xanthoma?

Xanthelasma. ***Xanthelasma*** - **Xanthelasma palpebrarum** is the most frequent type of xanthoma, characterized by soft, yellowish plaques that typically appear on the **eyelids**. - These lesions are common in the general population and may or may not be associated with **hyperlipidemia** or **dyslipidemia**. *Tuberous xanthoma* - Presents as **large, nodular lesions** typically found on **elbows, knees, and buttocks**, making them less common than eyelid xanthelasma. - Strongly associated with **familial hypercholesterolemia** and severe **hyperlipidemia**, limiting their prevalence. *Tendinous xanthoma* - Appears as **firm nodules** within **tendons**, particularly the **Achilles tendon** and **extensor tendons** of hands. - Less common due to their specific anatomical location and strong association with **familial hypercholesterolemia**. *Eruptive xanthoma* - Characterized by **small, yellow papules** that appear suddenly on **buttocks, shoulders, and extensor surfaces**. - Less frequent as they typically occur only during episodes of severe **hypertriglyceridemia** and often resolve with treatment.

Q: Consider the following statements regarding oculocutaneous albinism : I. The disease results from genetic abnormalities leading to destruction of melanocytes II. Type 1 albinism is due to a defect in the tyrosinase gene III. Patients may present with poor vision, rotator nystagmus and alternating strabismus IV. Patients are at an increased risk of sunburn or developing skin cancer Which of the statements given above are correct?

II, III and IV. ***II, III and IV*** - **Type 1 oculocutaneous albinism (OCA1)** is caused by mutations in the **tyrosinase gene (TYR)**, which encodes the enzyme tyrosinase essential for melanin synthesis [1]. - Patients commonly exhibit **poor vision**, **rotatory nystagmus**, and **alternating strabismus** due to abnormal foveal development and misrouting of optic nerve fibers [1]. - Due to the **lack of melanin**, which protects against UV radiation, these patients are at a significantly increased risk of **sunburn** and developing **skin cancers** like basal cell carcinoma and squamous cell carcinoma [1]. *I, II and IV* - The first statement is incorrect; albinism is characterized by a **defect in melanin production**, not the destruction of melanocytes. Melanocytes are present but are unable to produce or distribute melanin effectively [1]. - Statements II and IV are correct, but the inclusion of the incorrect statement I makes this option incorrect overall. *I, III and IV* - The first statement is incorrect because oculocutaneous albinism is due to **impaired melanin synthesis**, not the destruction of melanocytes. Melanocytes are typically present [1]. - Statements III and IV are correct, but the inaccuracy of statement I makes this choice incorrect. *I, II and III* - Statement I is factually incorrect; albinism stems from a **defect in melanin production or transport**, not the destruction of melanocytes [1]. - Statements II and III are correct, but the inclusion of the incorrect statement I renders this option invalid.

Q: A young girl presents with leukotrichia and lesions as shown in the image. What is the most likely diagnosis?

Segmental vitiligo. ***Segmental vitiligo*** - Segmental vitiligo characteristically presents as unilateral, **dermatomal** or **quasi-dermatomal depigmentation** with sharply demarcated borders, often including overlying **leukotrichia** (white hairs) in the affected area, as seen in the image. - This form typically has an early onset, rapid progression followed by stabilization, and can be more resistant to conventional treatments than non-segmental vitiligo. *Piebaldism* - Piebaldism is a **congenital leukoderma** characterized by a **white forelock** and symmetrically distributed depigmented patches, primarily on the trunk and extremities, which are usually stable in size and present from birth. - Unlike the progressive nature and unilateral pattern seen in the image, piebaldism is a genetic condition without new lesion development or the characteristic dermatomal distribution. *Focal vitiligo* - Focal vitiligo refers to one or a few localized depigmented macules that do not have a segmental pattern and are not distributed along a specific dermatome. - While it involves localized depigmentation, the clear **segmental distribution** and presence of **leukotrichia** in the image are more indicative of segmental vitiligo. *Nevus depigmentosus* - Nevus depigmentosus is a congenital, **stable hypopigmented lesion** that typically appears as a solitary patch or macule, without subsequent growth or change in size over time. - The lesions shown in the image appear to be multiple and follow a distinct pattern that is not typical of a stable, solitary nevus.

Q: A 28-year-old woman presents with progressive darkening of her face that started during pregnancy. The pigmentation is symmetrical and primarily affects her cheeks and forehead. It became more prominent with sun exposure. Examination reveals bilateral, symmetrical brown patches on her face. Which of the following is the most appropriate initial management?

Broad-spectrum sunscreen and sun avoidance. ***Broad-spectrum sunscreen and sun avoidance*** - The patient's presentation of **symmetrical facial hyperpigmentation** during pregnancy that worsens with sun exposure is characteristic of **melasma**. - **Photoprotection** with broad-spectrum sunscreen and strict sun avoidance is the cornerstone of initial management and prevention of melasma exacerbation. *Topical steroids* - Topical steroids are **anti-inflammatory agents** and are **not indicated** as primary treatment for melasma. - Their prolonged use on the face can lead to side effects such as **skin atrophy**, telangiectasias, and acne. *Oral isotretinoin* - Oral isotretinoin is primarily used for **severe acne** and is a potent teratogen, making it **contraindicated in pregnancy**. - It is **not effective** for the treatment of melasma. *Phototherapy* - Phototherapy, such as **UVB or UVA light therapy**, is used for conditions like psoriasis or eczema. - It would be **counterproductive** for melasma, as UV exposure actually worsens the condition.

Q: An 18-year-old woman was diagnosed 7 years earlier with precocious pseudopuberty secondary to ovarian tumor. Physical examination reveals oral and lingual dark pigmentation. (See Figure below). Which of the following is the most likely diagnosis?

Peutz-Jeghers syndrome. ***Peutz-Jeghers syndrome*** - The combination of **oral and lingual dark pigmentation** (mucocutaneous pigmentation) and a history of **precocious pseudopuberty** secondary to an **ovarian tumor** (specifically a sex cord tumor with annular tubules, or Sertoli cell tumor) is highly characteristic of Peutz-Jeghers syndrome. - This syndrome is also associated with **hamartomatous polyps** in the gastrointestinal tract and an increased risk of various cancers. *Gardner syndrome* - Characterized by **multiple colon polyps**, osteomas, dental abnormalities, and soft tissue tumors. - **Mucocutaneous pigmentation** and early onset ovarian tumors are not typical features. *Juvenile polyposis* - Defined by the presence of **multiple hamartomatous polyps** in the gastrointestinal tract, especially in the colon. - It does not typically present with **mucocutaneous pigmentation** or an association with ovarian tumors causing precocious pseudopuberty. *Lynch syndrome* - Also known as hereditary non-polyposis colorectal cancer (HNPCC), it is primarily associated with an increased risk of **colorectal cancer** and other cancers (e.g., endometrial, ovarian). - It does not involve **skin pigmentation** or typical associations with early childhood ovarian tumors.

Q: Which of the following is not true about hydroquinone?

It should not be used for melasma or chloasma of pregnancy. ***It should not be used for melasma or chloasma of pregnancy*** - This statement is **NOT TRUE** - hydroquinone is actually a **first-line treatment for melasma** including chloasma (melasma of pregnancy) - Hydroquinone 2-4% is one of the **most effective topical agents** for treating melasma and is widely recommended in dermatological guidelines - While hydroquinone use during **active pregnancy** is approached with caution (FDA Category C), it is definitely indicated for treating melasma/chloasma **after pregnancy** and for general melasma in non-pregnant patients - The condition (melasma/chloasma) is appropriately treated with hydroquinone; only the **timing during pregnancy** requires consideration *Response is incomplete and pigmentation may recur* - This is a **TRUE statement** about hydroquinone therapy - Treatment response is often **incomplete** with partial lightening of hyperpigmentation - **Recurrence is common** after discontinuation, especially with continued sun exposure or hormonal triggers - Maintenance therapy is often needed to sustain results *It inhibits tyrosinase* - This is a **TRUE statement** - hydroquinone's primary mechanism of action - Acts as a **competitive inhibitor of tyrosinase**, the rate-limiting enzyme in melanin synthesis - This inhibition reduces melanin production in melanocytes, leading to depigmentation *It requires prescription strength concentrations above 2%* - This is a **TRUE statement** in most countries including India and the USA - Hydroquinone concentrations **≤2%** are available over-the-counter (OTC) - Concentrations **>2% (typically 3-4%)** require a prescription - Higher concentrations provide greater efficacy but also increased risk of side effects like ochronosis

Question 1

The image shows presence of:

Accepted Answer

Nevus of Ota

Answer

Nevus spilus

Answer

Giant melanocytic nevus of face

Answer

Port wine stain

Question 2

A 24-year-old male presents with a lesion at the site shown in the image for 4 years. He says it has increased in thickness over the years. Diagnosis is:

Accepted Answer

Becker's nevus

Answer

Spitz nevus

Answer

Hyper-melanosis of Ito

Answer

Congenital melanocytic nevus

Question 3

A patient presents with the skin finding shown in the image. Identify the most likely diagnosis for this lesion.

Accepted Answer

Piebaldism

Answer

Vitiligo

Answer

Contact leukoderma

Answer

Albinism

Question 4

The clinical diagnosis is?

Accepted Answer

Albinism

Answer

Wilson disease

Answer

Menke's disease

Answer

Waardenburg syndrome

Question 5

The image shows Bilateral Xanthelasma palpebrarum. Which of the following is the most common type of xanthoma?

Accepted Answer

Xanthelasma

Answer

Tuberous xanthoma

Answer

Tendinous xanthoma

Answer

Eruptive xanthoma

Question 6

Consider the following statements regarding oculocutaneous albinism :
I. The disease results from genetic abnormalities leading to destruction of melanocytes
II. Type 1 albinism is due to a defect in the tyrosinase gene
III. Patients may present with poor vision, rotator nystagmus and alternating strabismus
IV. Patients are at an increased risk of sunburn or developing skin cancer

Which of the statements given above are correct?

Accepted Answer

II, III and IV

Answer

I, II and IV

Answer

I, III and IV

Answer

I, II and III

Question 7

A young girl presents with leukotrichia and lesions as shown in the image. What is the most likely diagnosis?

Accepted Answer

Segmental vitiligo

Answer

Piebaldism

Answer

Focal vitiligo

Answer

Nevus depigmentosus

Question 8

A 28-year-old woman presents with progressive darkening of her face that started during pregnancy. The pigmentation is symmetrical and primarily affects her cheeks and forehead. It became more prominent with sun exposure. Examination reveals bilateral, symmetrical brown patches on her face. Which of the following is the most appropriate initial management?

Accepted Answer

Broad-spectrum sunscreen and sun avoidance

Answer

Topical steroids

Answer

Oral isotretinoin

Answer

Phototherapy

Question 9

An 18-year-old woman was diagnosed 7 years earlier with precocious pseudopuberty secondary to ovarian tumor. Physical examination reveals oral and lingual dark pigmentation. (See Figure below). Which of the following is the most likely diagnosis?

Accepted Answer

Peutz-Jeghers syndrome

Answer

Gardner syndrome

Answer

Lynch syndrome

Answer

Juvenile polyposis

Question 10

Which of the following is not true about hydroquinone?

Accepted Answer

It should not be used for melasma or chloasma of pregnancy

Answer

Response is incomplete and pigmentation may recur

Answer

It inhibits tyrosinase

Answer

It requires prescription strength concentrations above 2%

Pigmentary Disorders — MCQs

Pigmentary Disorders — MCQs

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