Dermatitis Herpetiformis (DH)
Dermatitis Herpetiformis is a chronic, intensely pruritic autoimmune blistering disorder that is pathognomonic for Celiac Disease (gluten-sensitive enteropathy).
Key Clinical Features
- Lesions: Grouped, symmetrical, erythematous papules and vesicles.
- Distribution: Classic involvement of extensor surfaces (elbows, knees), buttocks, and the back.
- Symptomatology: Intense burning or pruritus, often leading to excoriations that obscure the primary vesicular lesions.
Diagnostic & Pathologic Hallmarks
| Test | Finding |
|---|---|
| Histopathology | Subepidermal blisters with neutrophil microabscesses at the dermal papillae. |
| Direct Immunofluorescence | Granular IgA deposits in the dermal papillae. |
High-Yield Exam Pearl:
- Management: First-line pharmacotherapy is Dapsone, which provides rapid relief of pruritus. Long-term management requires a strict gluten-free diet to resolve the underlying autoimmune enteropathy.
- Comparison: Note the difference in immunofluorescence patterns: Dermatitis Herpetiformis (Granular IgA) vs. Bullous Pemphigoid (Linear IgG/C3).