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 skin lesions is not classified as a nevus of melanocytes?

Becker nevus. ***Becker nevus*** - A **Becker nevus** is a **hamartoma** of the **epidermis, dermis, and hair follicles**, characterized by increased epidermal basal layer pigmentation and smooth muscle hyperplasia. - While it contains increased **melanin**, it does **not** involve a proliferation of **melanocytes** themselves, differentiating it from true melanocytic nevi. - It is an **organoid hamartoma** with epidermal and dermal components, not a melanocytic lesion. *Mongolian spot* - A **Mongolian spot** is a **dermal melanocytosis** where melanocytes are entrapped in the dermis during their migration from the neural crest to the epidermis. - While technically termed a "melanocytosis" rather than a "nevus," it represents an **ectopic collection of dermal melanocytes** and is classified among melanocytic lesions. - Unlike Becker nevus, it involves an actual abnormal distribution of melanocytes (not just increased melanin). *Congenital melanocytic nevus* - A **congenital melanocytic nevus** is a benign proliferation of **melanocytes** present at birth, involving the dermis and/or epidermis. - These are true **melanocytic nevi**, with a risk of malignant transformation, particularly in larger lesions (>20 cm). *Dysplastic nevus* - A **dysplastic nevus** (atypical nevus) is an atypical melanocytic nevus with architectural and cytological atypia, considered a potential precursor to melanoma. - It is classified as a **melanocytic nevus** due to the proliferation of atypical melanocytes with architectural disorder. [Practice more Dermatology PYQs on OnCourse]

Q: Which of the following is NOT a characteristic of dermatophytosis?

Subdermal infection. ***Subdermal infection*** - Dermatophytosis, or **ringworm**, is characterized by infection of the **superficial keratinized tissues** (skin, hair, nails) and does not typically extend into the subdermal layers. - While fungal infections can be systemic or deep, dermatophytes specifically are restricted to the **stratum corneum** and other dead keratinized structures. *Scaly skin* - **Scaling** is a very common characteristic of dermatophyte infections due to the fungus proliferating within the **stratum corneum**, leading to increased epidermal turnover and shedding. - The scaling can be fine or coarse, often presenting in an **annular (ring-like)** pattern. *Itchy skin* - **Pruritus (itching)** is a prominent symptom of dermatophytosis, often leading patients to seek medical attention. - The itching can range from mild to severe, contributing to discomfort and potential secondary skin excoriations. *Superficial infection* - Dermatophytosis is by definition a **superficial fungal infection**, meaning it is confined to the outermost layers of the skin, hair, and nails. - These fungi produce enzymes such as **keratinases** that allow them to digest keratin, but they generally do not invade viable tissue below the epidermis. [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 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 4

Which of the following is NOT a characteristic of dermatophytosis?

Accepted Answer

Subdermal infection

Answer

Scaly skin

Answer

Itchy skin

Answer

Superficial infection

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

What type of cell are Tzanck cells commonly associated with in skin conditions?

Accepted Answer

Keratinocyte

Answer

Neutrophil

Answer

Lymphocyte

Answer

Fibroblast

Question 7

Which of the following is NOT a feature of atopic dermatitis?

Accepted Answer

Darier’s Sign

Answer

Dennie-Morgan fold

Answer

Hyperlinearity of palms

Answer

Hertoghe’s sign

Question 8

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 9

Phrynoderma is primarily associated with a deficiency of which of the following?

Accepted Answer

Vitamin A

Answer

Essential fatty acid

Answer

Vitamin D

Answer

Niacin

Question 10

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

Accepted Answer

Lichen planus

Answer

Addison's disease

Answer

DM

Answer

Hypothyroidism

NEET-PG 2012 — Dermatology