Dermatitis herpetiformis is an autoimmune blistering skin disorder associated with coeliac disease. It is caused by deposition of IgA in the dermis. More than 90% of patients exhibit small bowel biopsy findings consistent with some degree of gluten-sensitive enteropathy.

Features

• itchy, vesicular skin lesions on the extensor surfaces (e.g. elbows, knees, buttocks)

Dermatitis herpetiformis in a middle-aged female who presented with pruritic vesicles on her knees and elbows. Image used on license from DermNet NZ

Diagnosis

• skin biopsy: direct immunofluorescence shows deposition of IgA in a granular pattern in the upper dermis

Management

• gluten-free diet
• dapsone