Dermatitis herpetiformis is associated with IgA deposits in the papillary dermis. These deposits are directed against which antigen?

• A Tissue transglutaminase (tTG2)
• B Desmoglein 3
• C Epidermal transglutaminase (eTG3) ✓
• D Endomysial antigen

Explanation

In DH, IgA autoantibodies primarily target epidermal transglutaminase (TG3), which is found in the papillary dermis. Tissue transglutaminase (TG2) is the main target in coeliac disease itself, but TG3-specific IgA forms the granular deposits in DH skin. Both TG2 and TG3 antibodies are elevated in DH, but TG3 is the direct skin antigen. DIF shows granular IgA in the papillary dermis — key distinction from linear IgA disease.

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.