NEET-PG 2021 - Dermatology PYQs Practice Questions

Q: A 30-year-old woman presents with flaccid bullae on her skin that are easy to rupture. A biopsy of the lesion reveals a suprabasal split. What is the most likely diagnosis?

Pemphigus vulgaris. ***Pemphigus vulgaris*** - Characterized by **flaccid bullae** that are easily ruptured, and a classic histological finding of a **suprabasal split** in the epidermis, indicating acantholysis just above the basal layer. - Mucosal involvement is common, and the positive **Nikolsky sign** (epidermal detachment with lateral pressure) is often present, which is typical for pemphigus vulgaris due to the superficial nature of the blistering. - The combination of **flaccid bullae + suprabasal split** is pathognomonic for pemphigus vulgaris. *Erythema multiforme* - Typically presents with **targetoid lesions** (concentric rings of erythema) and is often associated with infections, particularly herpes simplex virus (HSV). - Histologically, it shows **interface dermatitis** with vacuolar degeneration of basal cells and scattered necrotic keratinocytes, not a suprabasal split or acantholysis. *Pemphigus vegetans* - A rare variant of pemphigus vulgaris, it presents with **vegetating plaques** in intertriginous areas (axillae, groin), which are eroded but not primarily flaccid bullae covering wide areas. - While it also involves a suprabasal split at the same level as pemphigus vulgaris, the clinical presentation of vegetating plaques rather than widespread flaccid bullae helps differentiate it. *Pemphigus foliaceous* - This autoimmune blistering disease features very **superficial bullae** that rupture so easily they typically present as erosions, crusts, and scaling rather than intact blisters. - Histologically, it shows a **subcorneal or granular layer split** (more superficial than pemphigus vulgaris), not the deeper suprabasal split seen in this patient's biopsy. - Mucosal involvement is **rare** in pemphigus foliaceous, unlike pemphigus vulgaris. [Practice more Dermatology PYQs on OnCourse]

Q: A young girl presents to the outpatient department with rough-surfaced lesions over her elbows and knees. She also complains of diminished vision at night. What is the most likely diagnosis?

Phrynoderma. ***Phrynoderma*** - Phrynoderma, also known as **follicular hyperkeratosis**, presents with **rough, horny papules** over extensor surfaces like elbows and knees, often described as "toad skin." - It is a skin manifestation of **vitamin A deficiency**, which also causes **night blindness** (nyctalopia) due to impaired production of rhodopsin. *Folliculitis* - This is an **inflammation of hair follicles**, appearing as small, red bumps or pustules centered around hair follicles. - It is typically caused by bacterial or fungal infections and does not cause **night blindness**. *Pyoderma* - **Pyoderma** refers to a **pus-producing skin infection** caused by bacteria, such as impetigo or cellulitis. - These are characterized by crusts, blisters, or inflamed lesions and are not associated with **rough skin** or **night blindness**. *Keratosis pilaris* - This common genetic condition causes small, rough bumps, typically on the upper arms, thighs, and buttocks, due to **keratin plugging hair follicles**. - While it causes rough skin similar to phrynoderma, it is generally **benign** and does not cause systemic symptoms like **night blindness**. [Practice more Dermatology PYQs on OnCourse]

Question 1

A 30-year-old woman presents with flaccid bullae on her skin that are easy to rupture. A biopsy of the lesion reveals a suprabasal split. What is the most likely diagnosis?

Accepted Answer

Pemphigus vulgaris

Answer

Erythema multiforme

Answer

Pemphigus vegetans

Answer

Pemphigus foliaceous

Question 2

A 53 year-old male presented with erythematous, edematous plaques on his face over pre-existing hypoesthetic patches. He has been experiencing pain for the last 10 days and has been on multibacillary multidrug therapy (MBMDT) for leprosy for the past two months. What is the most likely diagnosis based on the image?

Accepted Answer

Type 1 Lepra reaction

Answer

Erythema Nodosum Leprosum (ENL)

Answer

Cellulitis of the face

Answer

Erysipelas

Question 3

A young girl presents to the outpatient department with rough-surfaced lesions over her elbows and knees. She also complains of diminished vision at night. What is the most likely diagnosis?

Accepted Answer

Phrynoderma

Answer

Folliculitis

Answer

Pyoderma

Answer

Keratosis pilaris

Question 4

A male child presents with a mildly painful swelling on his scalp for the last 3 months, as shown in the image. The history reveals that there is a pet dog in the household. What is the most likely diagnosis?

Accepted Answer

Kerion

Answer

Abscess

Answer

Scabies

Answer

Folliculitis

NEET-PG 2021 — Dermatology