Pigmentary Disorders — MCQs

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?

Q98

Which of the following chemical is responsible for the skin condition given below:

Q99

Which of the following is not true about hydroquinone?

Q100

False about melasma is?

Pigmentary Disorders Indian Medical PG Practice Questions and MCQs

Question 91: 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:

A. Spitz nevus
B. Hyper-melanosis of Ito
C. Becker's nevus (Correct Answer)
D. Congenital melanocytic nevus

Explanation: ***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.

Question 92: Which is not correct about the lesion shown below?

A. The lesions are infectious to seronegative individuals
B. Can be associated with meningoencephalitis
C. Bilaterally symmetrical dermatomal vesicular eruption (Correct Answer)
D. Geniculate ganglion is involved in Ramsay hunt syndrome

Explanation: ***Bilaterally symmetrical dermatomal vesicular eruption*** - The image shows a **unilateral, dermatomal vesicular eruption**, characteristic of herpes zoster (shingles). - Herpes zoster lesions are typically restricted to **one side of the body** and follow a single dermatome, making bilateral symmetry incorrect. *The lesions are infectious to seronegative individuals* - The vesicles of herpes zoster contain **live varicella-zoster virus (VZV)**, which can be transmitted through direct contact. - Individuals who have not previously had chickenpox (seronegative for VZV) can contract **chickenpox** (not shingles) from exposure to these lesions. *Can be associated with meningoencephalitis* - Although rare, disseminated herpes zoster can lead to severe complications, including **meningoencephalitis** if the virus spreads to the central nervous system. - This complication is more likely in **immunocompromised individuals**. *Geniculate ganglion is involved in Ramsay hunt syndrome* - **Ramsay Hunt syndrome (Herpes zoster oticus)** is a specific complication of VZV reactivation involving the **geniculate ganglion** of the facial nerve. - This involvement leads to facial nerve palsy, ear pain, and typical vesicular rash in the ear canal or on the auricle.

Question 93: What is the best management of the case shown?

A. Dapsone plus steroids
B. Stop smoking and screen for cancer (Correct Answer)
C. Vitamin supplements
D. Antifungals for oral candidiasis

Explanation: ***Stop smoking and screen for cancer*** - The image shows **smoker's palate (nicotinic stomatitis)**, characterized by diffuse white thickening of the palatal mucosa with red dots representing inflamed salivary gland orifices. This condition is caused by **chronic heat exposure from smoking**. - While generally benign, smoker's palate indicates a high risk for other **oral cancers**, particularly those involving the lips, tongue, and floor of the mouth, necessitating smoking cessation and regular screening. *Dapsone plus steroids* - This combination is typically used for **autoimmune blistering diseases** like **dermatitis herpetiformis** or **pemphigoid**, which present with different clinical features. - Smoker's palate is not an autoimmune condition and would not respond to these treatments. *Vitamin supplements* - Vitamin supplements are not a treatment for smoker's palate, as it is a localized lesion caused by irritation from smoke. - While general nutritional support is good, it doesn't address the underlying cause or potential complications of this specific condition. *Antifungals for oral candidiasis* - **Oral candidiasis (thrush)** typically presents as removable white plaques on the oral mucosa, often associated with immunosuppression or antibiotic use. - The lesions in the image are firmly attached, non-removable, and show specific morphological changes (red dots), which are not characteristic of candidiasis.

Question 94: The image shows Bilateral Xanthelasma palpebrarum. Which of the following is the most common type of xanthoma?

A. Xanthelasma (Correct Answer)
B. Tuberous xanthoma
C. Tendinous xanthoma
D. Eruptive xanthoma

Explanation: ***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.

Question 95: A 30-year-old male presents with joint pain and NSAIDs were prescribed. After one week, joint pain is persisting and he has developed brownish discoloration over nose as shown in the figure. This was due to: (AIIMS Nov 2017)

A. Melasma
B. Chikungunya
C. Fixed drug eruption (Correct Answer)
D. Dengue

Explanation: ***Fixed drug eruption*** - A **fixed drug eruption (FDE)** is a localized cutaneous drug reaction that characteristically **recurs at the same site** upon re-exposure to the offending drug, presenting as well-demarcated erythematous patches, plaques, vesicles, or bullae that heal with **post-inflammatory hyperpigmentation** (brownish discoloration). - NSAIDs (particularly phenylbutazone, oxicams, and diclofenac) are among the **most common causes** of fixed drug eruption. The scenario describes **brownish discoloration on the nose** appearing one week after NSAID use, which represents the characteristic hyperpigmentation phase of FDE. - The **timing** (within 1-2 weeks of drug exposure), **localized distribution** (single site on nose), and **clinical presentation** (brownish patch after medication) are pathognomonic for fixed drug eruption. *Melasma* - **Melasma** causes symmetrical, patchy hyperpigmentation typically on sun-exposed facial areas (malar eminences, forehead, upper lip) and is associated with **hormonal factors** (pregnancy, oral contraceptives) or chronic sun exposure. - It develops **gradually over months**, not acutely within one week of medication use, and shows a bilateral, symmetrical pattern rather than a localized unilateral presentation. *Chikungunya* - **Chikungunya** is a mosquito-borne viral infection presenting with acute fever, severe polyarthralgia, and a **maculopapular or petechial rash** that appears during the febrile phase. - The rash is typically generalized and erythematous, not a localized brownish hyperpigmented patch. While joint pain is prominent, the temporal relationship with NSAID use and the specific skin finding (brownish discoloration post-medication) point away from viral arthritis. *Dengue* - **Dengue** fever presents with high fever, retro-orbital headache, myalgia, and a characteristic **blanching maculopapular or petechial rash** appearing 2-5 days after fever onset. - The rash is typically generalized and associated with systemic features (fever, thrombocytopenia, bleeding manifestations), not a localized brownish patch appearing after NSAID therapy without fever.

Question 96: A young girl presents with leukotrichia and lesions as shown in the image. What is the most likely diagnosis?

A. Segmental vitiligo (Correct Answer)
B. Piebaldism
C. Focal vitiligo
D. Nevus depigmentosus

Explanation: ***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.

Question 97: 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?

A. Topical steroids
B. Oral isotretinoin
C. Broad-spectrum sunscreen and sun avoidance (Correct Answer)
D. Phototherapy

Explanation: ***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.

Question 98: Which of the following chemical is responsible for the skin condition given below:

A. Hydroquinone
B. Psoralen (Correct Answer)
C. Monobenzyl ether of hydroquinone (MBEH)
D. Para-tertiary butyl phenol (PTBP)

Explanation: ***Psoralen*** - **Psoralens (furocoumarins)** are the causative agents for **phytophotodermatitis** shown in the image - Found naturally in **citrus fruits (limes, lemons), celery, parsley, figs** and other plants - Mechanism: **Phototoxic reaction** when psoralen-containing plant material contacts skin followed by **UV light exposure** - Clinical features: **Linear or drip-pattern hyperpigmentation** corresponding to areas of plant juice contact, often with preceding erythema and blistering - This is the **classic presentation** seen with lime juice exposure ("margarita dermatitis") *Hydroquinone* - Used for **skin lightening** in melasma and hyperpigmentation disorders - Can cause **exogenous ochronosis** (blue-black pigmentation) with prolonged use - Does **not cause phototoxic reactions** with the linear pattern shown in the image - Side effects include irritant dermatitis, but not the characteristic distribution seen here *Monobenzyl ether of hydroquinone (MBEH)* - Permanent **depigmenting agent** used in extensive vitiligo - Causes **permanent destruction of melanocytes** leading to depigmentation - The image shows **hyperpigmentation**, not depigmentation, ruling this out - Can cause contact dermatitis but not phototoxic reactions *Para-tertiary butyl phenol (PTBP)* - Industrial chemical causing **leukoderma** (depigmentation) with occupational exposure - Historically found in **leather adhesives** and germicidal detergents - Causes **patchy depigmentation**, not the linear hyperpigmentation shown - Mechanism is melanocyte destruction, opposite to the clinical picture

Question 99: Which of the following is not true about hydroquinone?

A. Response is incomplete and pigmentation may recur
B. It inhibits tyrosinase
C. It requires prescription strength concentrations above 2%
D. It should not be used for melasma or chloasma of pregnancy (Correct Answer)

Explanation: ***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 100: False about melasma is?

A. More common in male (Correct Answer)
B. Hydroquinone has role in the treatment
C. Commonly affects sun-exposed areas
D. Oral contraceptives can induce it

Explanation: ***More common in male*** - **Melasma** is significantly **more common in females** (90%) than in males (10%), especially among women of childbearing age. - This strong female predominance is linked to **hormonal factors**, such as pregnancy and oral contraceptive use. - **This statement is FALSE**, making it the correct answer to this negation question. *Hydroquinone has role in the treatment* - **Hydroquinone** is a **first-line topical treatment** for melasma, working by inhibiting melanin synthesis. - It helps lighten hyperpigmented patches by reducing the activity of **tyrosinase**, a key enzyme in melanin production. *Commonly affects sun-exposed areas* - **Melasma** typically presents on **sun-exposed areas** of the face, particularly the cheeks, forehead, upper lip, and chin. - **UV exposure** is a major triggering and exacerbating factor, which is why sun protection is crucial in management. *Oral contraceptives can induce it* - **Oral contraceptive pills** are a well-known trigger for **melasma**, due to the hormonal changes they induce (estrogen and progesterone). - The elevated **hormone levels** stimulate melanocytes, leading to increased melanin production and hyperpigmentation.

Practice by Chapter

Melanocyte Biology

Practice Questions

Vitiligo

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Melasma

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Post-inflammatory Hyperpigmentation

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Post-inflammatory Hypopigmentation

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Albinism

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Drug-Induced Pigmentary Changes

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Pityriasis Alba

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Pigmentary Demarcation Lines

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Nevi of Ota and Ito

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Management of Hyperpigmentation

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Management of Hypopigmentation

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