Dermatitis herpetiformis
Dermatitis herpetiformis is an intensely pruritic, symmetric, grouped vesicular and papular eruption on extensor surfaces that is a cutaneous manifestation of gluten-sensitive enteropathy (celiac disease). Diagnosis rests on skin biopsy with direct immunofluorescence plus celiac serology, and treatment combines a strict lifelong gluten-free diet with dapsone (starting 50 mg PO once daily, titrated within 50 to 300 mg daily) for rapid control of the itch while the diet takes effect.
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What this article covers
- Overview
Definition: dermatitis herpetiformis is an intensely pruritic, blistering skin disease that is the cutaneous manifestation of gluten-sensitive enteropathy (celiac disease).
- Epidemiology
Onset in adulthood: the eruption usually begins in the third or fourth decade of life.
- Risk factors
Gluten-sensitive enteropathy (celiac disease): the essential predisposing condition, since dermatitis herpetiformis is its cutaneous manifestation.
- Pathophysiology
Cutaneous expression of gluten-sensitive enteropathy: the skin eruption is a direct manifestation of the same gluten-driven immune process that produces celiac disease in the gut, even when gastrointestinal symptoms are absent.
- Clinical features
Grouped "herpetiform" vesicles: very itchy, grouped vesicles are symmetrically distributed on extensor surfaces, classically the elbows, knees, scalp, back, buttocks, and tip of the nose.
- Differential diagnosis
Bullous pemphigoid: large, tense blisters and bullae with a negative Nikolsky sign in patients typically over 60 years old that spare mucous membranes, unlike the smaller, intensely itchy, grouped…
- Diagnosis
Diagnose with skin biopsy plus celiac serology: the diagnostic basis is a skin biopsy sent for hematoxylin and eosin and direct immunofluorescence (DIF), which shows immunofluorescence at the…
- Management
First, start a strict, lifelong gluten-free diet, which is the essential treatment for both the intestinal and cutaneous disease.
- Complications
Enteropathy-associated T-cell lymphoma: gluten-sensitive enteropathy carries an increased lifetime risk of small bowel malignancy, most commonly enteropathy-associated T-cell lymphoma.
- Prognosis
Skin disease responds well to dapsone: dapsone rapidly controls the pruritic skin eruption while the slower-acting gluten-free diet takes effect.
- Prevention
Strict, lifelong gluten avoidance is the primary preventive measure, since only adherence to a gluten-free diet reduces the associated malignancy risk of the underlying gluten-sensitive enteropathy.
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