QuestionSBA
QuestionChoice
Erythema multiforme (EM) is also a hypersensitivity reaction that in 90% of cases is triggered by infection. The commonest infective cause is Herpes simplex virus. It presents with well-defined circular papules which evolve at different stages to form a 'target-shaped' lesion of three concentric rings of different colours. The rash tends to start on the palms/soles and spreads up the limbs to the trunk.
10005345
e
Erythema multiforme
QuestionChoice
This is a condition most often seen in children with atopic eczema. It often presents as a rapidly progressing painful rash. On examination, monomorphic punched-out erosions (circular, depressed, ulcerated lesions) usually 1–3 mm in diameter are typically seen.
10005344
d
Eczema herpeticum
QuestionChoice
This is a type II hypersensitivity reaction condition most often seen in the elderly. It presents with deep, tense blisters. Unlike pemphigus vulgaris, the oral mucosa is rarely affected, although this is not mentioned here. Nikolsky sign is negative importantly.
10005341
a
Bullous pemphigoid
QuestionChoice
This condition typically features fragile, superficial blisters that rupture easily and desquamation. Nikolsky sign is most often positive.
10005342
b
Pemphigus vulgaris
QuestionChoice
This is an autoimmune blistering condition but is associated with coeliac disease. It presents with itchy, vesicular skin lesions on the extensor surfaces (e.g. elbows, knees, buttocks). It is slightly more common in men too.
10005343
c
Dermatitis herpetiformis
Concept
Chapter
2693
3916
pemphigus and pemphigoid
Topic
144
Dermatology
13615
A 78-year-old female admitted for falls is reviewed by the dermatology doctors on the geriatric ward. She has itchy, tense and firm fluid-filled blisters symmetrically distributed over her trunk only. Nikolsky's sign is negative.

Which of the following is the most likely explanation for this patient’s physical findings?
a