Dermatitis Herpetiformis

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Snapshot

  • A 33-year-old man has a 2 year history of recurrent blistering, and itchy eruptions, especially on his forearms. There are no exacerbating factors. He reports no gastrointestinal symptoms. He has a past medical history of hypothyroidism.

Introduction

  • Chronic autoimmune skin disease
    • IgA anti-transglutaminase immune complex
    • considered cutaneous manifestation of celiac disease 
  • Epidemiology
    • males affected more than females (2:1)
    • onset in adulthood
  • Associated conditions
  • other autoimmune conditions such as thyroid disease

Presentation

  • Skin findings
    • severely itchy and burning blistering eruption
    • clustered papules, vesicles, or excoriations
    • symmetric distribution, especially on elbows and knees
    • oral lesions uncommon
  • Other findings
  • typically no gastrointestinal symptoms

Evaluation

  • Skin biopsy
    • gold standard
    • direct immunofluorescence showing deposits of IgA at tips of dermal papillae 
    • subepidermal vesicles with neutrophilic infiltrate
  • Small bowel biopsy
    • villous atrophy
  • Serologic testing
    • endomysial antibodies
    • tissue transglutaminase antibodies
  • epidermal transglutaminase antibodies

Differential Diagnosis

  • Scabies (intense unremitting itching)
  • Atopic dermatitis

Treatment

  • Lifestyle modifications
    • gluten-free diet
  • Pharmacological
  • dapsone

Prognosis, Prevention, and Complications

  • Prognosis
    • chronic disease
    • spontaneous remission in 1/3 of cases
  • Prevention
    • can be well-controlled with dapsone or gluten-free diet
  • Complications
    • typically none