PATH - Blistering Skin Disorders

Question 1

Pemphigus vulgaris

Answer 1

Potentially fatal autoimmune skin disorder with *IgG antibody against *desmoglein (component of *desmosomes)

Flaccid intraepidermal bull
*oral mucosa also involved

Nikolsky sign ⊕ (separation of epidermis upon manual stroking of skin).

Question 2

Bullous pemphigoid

Answer 2

*Less severe than pemphigus vulgaris.

Involves *IgG antibody against *hemidesmosomes (epidermal
basement membrane; antibodies are “bullow” the epidermis)

Tense blisters containing eosinophils affect skin but *spare oral mucosa

Nikolsky sign ⊝

Question 3

Dermatitis herpetiformis

Answer 3

Pruritic papules, vesicles, and bullae (often found on elbows)

Deposits of *IgA at tips of dermal papillae

Associated with *celiac disease

Question 4

Erythema multiforme

Answer 4

Presents with multiple types of lesions—macules, papules, vesicles, target lesions

Associated with infections (eg, Mycoplasma pneumoniae, HSV), drugs (eg, sulfa drugs, β-lactams, phenytoin), cancers, autoimmune disease

Question 5

Stevens-Johnson syndrome

Answer 5

Characterized by fever, bullae formation and necrosis, sloughing of skin at *dermal-epidermal junction, high mortality rate

Typically 2 mucous membranes are involved and targetoid
skin lesions may appear, as seen in erythema multiforme

Usually associated with adverse drug reaction.

A more severe form of Stevens-Johnson syndrome (SJS) with > 30% of the body surface
area involved is *toxic epidermal necrolysis (TEN).

10–30% involvement denotes SJS-TEN.