NEET-PG 2012 - Dermatology PYQs Practice Questions

Q: Raindrop pigmentation is caused by?

Arsenic. ***Arsenic*** - Chronic **arsenic** exposure can lead to characteristic skin manifestations, including **raindrop pigmentation**, which appears as small, scattered hypopigmented macules surrounded by hyperpigmented skin, particularly on the trunk and extremities. - This pigmentation is a result of altered **melanin distribution** and **keratinocyte damage** due to arsenic toxicity. *Clofazimine* - **Clofazimine** is an anti-leprosy drug that can cause **reddish-brown to bluish-black skin discoloration**, which is a diffuse pigmentation, not "raindrop" in nature. - The pigmentation associated with clofazimine is due to drug deposition in tissues and is usually reversible. *Dapsone* - **Dapsone** is primarily known for causing **methemoglobinemia** and **hemolytic anemia**, especially in patients with G6PD deficiency. - While it can cause some dermatological side effects, **pigmentation** is not a characteristic feature, and it does not produce a "raindrop" pattern. *Minocycline* - **Minocycline** can cause various types of pigmentation, including **blue-gray discoloration** in scars, shins, and mucous membranes, as well as diffuse brown pigmentation. - However, the pigmentation caused by minocycline is typically diffuse or localized to specific areas, and it does not present as "raindrop pigmentation." [Practice more Dermatology PYQs on OnCourse]

Q: Which of the following is NOT a characteristic of pemphigus vulgaris?

Subepidermal bulla. ***Subepidermal bulla*** - Pemphigus vulgaris is characterized by **intraepidermal bullae** resulting from acantholysis (loss of cohesion between keratinocytes), not subepidermal bullae. - **Subepidermal bullae** are characteristic of conditions like **bullous pemphigoid**, where the split occurs below the epidermis. *Positive Nikolsky’s sign* - The **Nikolsky's sign** is positive in pemphigus vulgaris, indicating the fragility of the skin where gentle lateral pressure causes epidermal shearing. - This sign is a direct result of the **intraepidermal blistering** due to weakened cell-to-cell adhesion. *Oral erosions* - **Oral erosions** are a very common and often the initial manifestation of pemphigus vulgaris, frequently preceding skin lesions. - These painful erosions are persistent and heal slowly, sometimes making eating difficult. *Tzanck smear showing acantholytic cells* - A **Tzanck smear** from a fresh blister in pemphigus vulgaris typically reveals **acantholytic cells**, which are detached, rounded keratinocytes with basophilic cytoplasm. - The presence of acantholytic cells confirms the **loss of intercellular adhesion** within the epidermis, a hallmark of pemphigus. [Practice more Dermatology PYQs on OnCourse]

Q: Itchy purple papule followed by hyperpigmentation on resolution, is seen in?

Lichen planus. ***Correct: Lichen planus*** - This condition presents with characteristic **pruritic (itchy) violaceous (purple) papules** that often develop **post-inflammatory hyperpigmentation** upon resolution. - The classic presentation follows the **"5 P's": Purple, Pruritic, Polygonal, Planar, Papules**. - Lesions commonly affect the **wrists, ankles, lower back, and genitals**, and may also involve the **oral mucosa** (Wickham's striae). - The hyperpigmentation on resolution is due to **melanin incontinence** and dermal melanophages. *Incorrect: Addison's disease* - Characterized by **hyperpigmentation**, but this is typically diffuse, affecting sun-exposed areas, pressure points, and mucous membranes (e.g., gum line), not discrete papules. - The pigmentation is due to increased **ACTH stimulating melanocytes**, without an initial itchy papular stage. *Incorrect: DM (Diabetes Mellitus)* - Diabetes Mellitus can cause various skin manifestations, including **acanthosis nigricans**, necrobiosis lipoidica diabeticorum, and diabetic dermopathy. - These manifestations do not typically present as itchy purple papules followed by hyperpigmentation, but rather as thickened, velvety skin folds or atrophic, pigmented lesions. *Incorrect: Hypothyroidism* - Can lead to **dry, coarse skin**, and occasionally **non-pitting edema** (myxedema). - It does not present with itchy purple papules or lesions that resolve with hyperpigmentation. [Practice more Dermatology PYQs on OnCourse]

Q: Which of the following is the MOST characteristic feature of skin tags (acrochordons)?

They are typically pedunculated.. ***They are typically pedunculated.*** - **Skin tags (acrochordons)** are benign soft tissue tumors characterized by their **pedunculated morphology** - they are attached to the skin by a narrow stalk or pedicle. - This **pedunculated appearance** is the **most characteristic** and **defining feature** that distinguishes them from other benign skin lesions. - They are typically **soft, flesh-colored or hyperpigmented**, and range from 1-5 mm in size. *They commonly occur on the neck and axilla.* - While **skin tags** frequently occur in areas of friction such as the neck, axilla, eyelids, groin, and inframammary folds, this **location is not specific**. - Many other skin conditions also favor these sites, so location alone is not a characteristic diagnostic feature. *They are associated with seborrhoeic keratosis.* - There is **no established clinical association** between skin tags and seborrheic keratoses. - Both are common **benign skin growths** in adults but represent different pathological entities with different clinical appearances. *They have malignant potential.* - This is **incorrect**. Skin tags are **benign fibrous polyps** with **no malignant potential**. - They do not require removal unless symptomatic or for cosmetic reasons. [Practice more Dermatology PYQs on OnCourse]

Question 1

Which of the following statements is true regarding donovanosis?

Accepted Answer

Painless ulcerative lesions are characteristic of donovanosis

Answer

Pseudolymphadenopathy is characteristic

Answer

Penicillin is used for treatment

Answer

Painful ulcer is characteristic

Question 2

Raindrop pigmentation is caused by?

Accepted Answer

Arsenic

Answer

Dapsone

Answer

Minocycline

Answer

Clofazimine

Question 3

Which of the following is NOT a characteristic of pemphigus vulgaris?

Accepted Answer

Subepidermal bulla

Answer

Oral erosions

Answer

Tzanck smear showing acantholytic cells

Answer

Positive Nikolsky’s sign

Question 4

Itchy purple papule followed by hyperpigmentation on resolution, is seen in?

Accepted Answer

Lichen planus

Answer

Addison's disease

Answer

DM

Answer

Hypothyroidism

Question 5

Which of the following is the MOST characteristic feature of skin tags (acrochordons)?

Accepted Answer

They are typically pedunculated.

Answer

They commonly occur on the neck and axilla.

Answer

They have malignant potential.

Answer

They are associated with seborrhoeic keratosis.

Question 6

Which of the following is not a feature of dermatomyositis?

Accepted Answer

Salmon Patch

Answer

Periungual telangiectasias

Answer

Gottron's patch

Answer

Mechanic's hands

Question 7

In which of the following conditions is the Koebner phenomenon most commonly observed?

Accepted Answer

Psoriasis

Answer

Lichen planus

Answer

All of the options

Answer

Viral warts

Question 8

What is the first symptom of leprosy?

Accepted Answer

Decreased pain

Answer

Decreased vibration & position sense

Answer

Decreased temperature

Answer

Decreased light touch

Question 9

Which of the following skin lesions is not classified as a nevus of melanocytes?

Accepted Answer

Becker nevus

Answer

Dysplastic nevus

Answer

Congenital melanocytic nevus

Answer

Mongolian spot

Question 10

Which of the following pairs of conditions is incorrectly matched?

Accepted Answer

Erythema chronicum migrans - malignancy

Answer

Erythema gyratum repens - malignancy

Answer

Erythema marginatum - rheumatic fever

Answer

Necrotic acral erythema - HCV

NEET-PG 2012 — Dermatology