MD MD - Doctor of Medicine Dermatology and Skin Disorders Questions and Answers 2

Question 1

Acne vulgaris is primarily caused by which organism?

Accepted Answer

Cutibacterium acnes

Answer

Acne vulgaris is primarily caused by Cutibacterium acnes (formerly Propionibacterium acnes), which colonizes hair follicles in sebum-rich areas.

Question 2

Which topical agent is considered first-line for mild-to-moderate acne vulgaris?

Accepted Answer

Benzoyl peroxide

Answer

Benzoyl peroxide is first-line topical treatment for mild-to-moderate acne due to its antibacterial, keratolytic, and comedolytic properties.

Question 3

Tinea versicolor (pityriasis versicolor) is caused by which organism?

Accepted Answer

Malassezia furfur

Answer

Tinea versicolor is caused by Malassezia furfur, a lipophilic dimorphic yeast that normally colonizes the skin's stratum corneum.

Question 4

Allergic contact dermatitis is a type IV hypersensitivity reaction mediated by:

Accepted Answer

T lymphocytes (delayed-type)

Answer

Allergic contact dermatitis is a type IV (cell-mediated/delayed-type) hypersensitivity reaction mediated by sensitized T lymphocytes.

Question 5

Which classic description applies to varicella (chickenpox) skin lesions?

Accepted Answer

Dew drops on a rose petal

Answer

Varicella lesions are classically described as 'dew drops on a rose petal' — clear vesicles on an erythematous base at various stages of evolution.

MD - Doctor of Medicine Practice Test