A chronic autoimmune subepidermal bullous disease characterized by grouped pruritic lesions such as papules, urticarial plaques, erythema, and herpetiform vesiculae, with a predominantly symmetrical distribution on extensor surfaces of the elbows (90%), knees (30%), shoulders, buttocks, sacral region, and face of children and adults. Erosions, excoriations and hyperpigmentation usually follow. It may also appear as a consequence of gluten intolerance.

Inflammation of the sac-like covering around the heart (pericardium).