Familial granuloma annulare. Report of two cases and review of the literature.

We report two sisters with granuloma annulare who possessed identical histocompatibility antigens. The occurrence of granuloma annulare in families and the demonstration of particular human lymphocyte antigens (HLA) with granuloma annulare may indicate that hereditarily predisposed individuals could develop this specific cell-mediated immune reaction in response to an unknown antigen (e.g., connective tissue or infectious or toxic substances).