HLA antigens in juvenile dermatitis herpetiformis.

The incidence of histocompatibility antigens HLA-A, B, C, DR was studied in 32 Italian children with dermatitis herpetiformis. A significantly increased relative risk was found for B8 (R.R.=6.2), which was present in 50% of the patients as against 14% of the controls and for DR3 (R.R.=11.7), present in 69% of the patients as against 16%. DR7 also appeared to be increased, but only among DR3-negative patients. There was no significant difference in the incidence of DR3 between children with abnormal and normal jejunal biopsy, though there does seem to be a difference in expressivity of the intestinal involvement between DR3 apparent homozygous, DR3 heterozygous and DR3-negative patients.