A 64-year-old man comes to the office due to blisters on his trunk and groin. Itching has occurred for the past several weeks, and blisters developed a week ago. He has a history of hypertension and osteoarthritis. The patient received the zoster vaccine at age 60. Examination shows numerous 0.5- to 3-cm bullous skin lesions. The findings from a skin biopsy are shown in the image below: Which of the following is the most likely diagnosis?

Question

A 64-year-old man comes to the office due to blisters on his trunk and groin.  Itching has occurred for the past several weeks, and blisters developed a week ago.  He has a history of hypertension and osteoarthritis.  The patient received the zoster vaccine at age 60.  Examination shows numerous 0.5- to 3-cm bullous skin lesions.  The findings from a skin biopsy are shown in the image below:  Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

11ec160b_38f0_81fd_9249_79ba41053571_MD0001_00 Bullous pemphigoid (BP) is an autoimmune blistering disease characterized by serous fluid-filled, tense bullae on normal or erythematous skin. The most common sites of involvement include the inner thighs and flexor aspects of the forearms, axillae, groin, and lower abdomen. Elderly individuals are most commonly affected. BP is caused by antibodies against hemidesmosomes along the basement membrane of the dermal-epidermal junction. These autoantibodies result in a destructive inflammatory cascade that causes the entire epidermis to separate from the dermis, forming subepidermal, nonacantholytic blisters. Immunofluorescence shows IgG and/or C3 deposits in a linear pattern along the basement membrane. (Choice B) Acute allergic contact dermatitis is characterized by localized erythema, vesicles, edema, and severe pruritus. Biopsy typically shows spongiosis (abnormal accumulation of edema fluid in the intercellular spaces between keratinocytes) and lymphocytic perivascular infiltrates but no separation of the epidermis from the dermis. (Choice C) Dermatitis herpetiformis presents with small, pruritic papules and vesicles over extensor surfaces and is characterized histologically by microabscesses containing fibrin and neutrophils at the dermal papillae tips. The overlying basal cells become vacuolated, and blisters form at the tips of the involved papillae. (Choice D) Lichen planus causes pruritic, purple papules and plaques involving the skin and mucous membranes (not blisters). Microscopic analysis shows a lymphocytic infiltrate at the dermal-epidermal junction with destruction of basal epidermal cells. (Choice E) Pemphigus vulgaris is due to autoantibodies directed against desmosomal proteins. Biopsy of an active pemphigus lesion shows intraepithelial cleavage with detached keratinocytes (acantholysis), retained keratinocytes along the basement membrane, and an eosinophilic inflammatory infiltrate. Educational objective: Bullous pemphigoid is caused by autoantibodies against hemidesmosomes along the basement membrane of the dermal-epidermal junction. This causes the entire epidermis to separate from the dermis and form tense, subepidermal blisters. __________ References: Bullous pemphigoid. (http://www.ncbi.nlm.nih.gov/pubmed/31090818)

A 64-Year-Old Man Comes to the Office Due to Blisters