Dermatologic Conditions & Diseases Flashcards
7 cards from real CDT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Dermatologic Conditions & Diseases flashcards as text
Which hallmark sign is used to diagnose pemphigus vulgaris at the bedside, where lateral pressure on unblistered skin causes shearing of the epidermis?
Answer: Nikolsky sign
A positive Nikolsky sign, elicited by applying lateral shear pressure to normal-appearing skin to produce blistering, is characteristic of pemphigus vulgaris.
A patient presents with pruritic papules and burrows between the finger webs and on the wrists. What is the most likely diagnosis?
Answer: Scabies
Scabies, caused by Sarcoptes scabiei mite infestation, characteristically presents with intensely pruritic papules and linear burrows in web spaces, wrists, and genitalia.
Erythema multiforme minor is most commonly triggered by:
Answer: Herpes simplex virus infection
Herpes simplex virus (HSV) infection is the most common trigger for erythema multiforme minor, which presents with target lesions on the extremities.
Which feature distinguishes irritant contact dermatitis from allergic contact dermatitis?
Answer: Allergic CD requires prior sensitization; irritant CD does not
Allergic contact dermatitis is a Type IV (delayed) hypersensitivity reaction requiring prior sensitization, whereas irritant contact dermatitis results from direct chemical damage without immune memory.
A patient with a port-wine stain on one side of the face and ipsilateral leptomeningeal angiomatosis causing seizures most likely has which syndrome?
Answer: Sturge-Weber syndrome
Sturge-Weber syndrome is a neurocutaneous disorder characterized by a facial port-wine stain (trigeminal distribution), ipsilateral leptomeningeal angiomas, and neurological complications including seizures.
Lichen planus is classically described using which set of descriptive terms?
Answer: Four Ps: Pruritic, Purple, Polygonal, Papules
Lichen planus is memorably described by the '4 Ps': Pruritic, Purple (violaceous), Polygonal, flat-topped Papules, often with Wickham's striae on the surface.
Which skin finding is most characteristic of tuberous sclerosis complex?
Answer: Ash-leaf macules (hypomelanotic macules)
Ash-leaf macules (hypomelanotic macules visible under Wood's lamp) are the earliest and most common cutaneous sign of tuberous sclerosis complex, often present at birth.