A 35-year-old woman with celiac disease develops intensely pruritic papulovesicles symmetrically distributed over extensor surfaces of elbows and knees. Perilesional DIF shows granular IgA deposits in dermal papillae. The autoantigen is:

• A Epidermal transglutaminase 3 ✓
• B Tissue transglutaminase 2
• C BP230
• D Type VII collagen

Explanation

Dermatitis herpetiformis (DH) is associated with celiac disease; serum IgA anti-tissue transglutaminase (TG2) antibodies are elevated, but the actual cutaneous autoantigen is epidermal transglutaminase (TG3 / TGase 3). Granular IgA deposits in the dermal papillae on DIF is pathognomonic. Type VII collagen is the target in epidermolysis bullosa acquisita; BP230 in bullous pemphigoid. Treatment requires gluten-free diet plus dapsone.

Reference: Neena Khanna Illustrated Synopsis of Dermatology & STD, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.