Intercellular IgA dermatosis (IgA pemphigus) - two cases illustrating the clinical heterogeneity of this disorder

IgA pemphigus is rare but may be underdiagnosed. We describe two cases, a 5 0-year-old female with a pustular eruption resembling subcorneal pustular d ermatosis and a 55-year-old male with a pruritic vesiculopustular eruption simulating dermatitis herpetiformis. They illustrate the clinical heterogen eity of IgA pemphigus which is likely to reflect differences in autoantigen s, analogous to pemphigus vulgaris and pemphigus foliaceus. There is now ev idence that IgA pemphigus encompasses at least two subgroups: a subcorneal pustular dermatosis (SPD)-type, (see case 1) characterized by subcorneal pu stules and autoantibodies to desmocollin 1; and intra-epidermal neutrophili c dermatosis (IEN)-type cases (see case 2) which show intra-epidermal pustu les and in whom the autoantigen may be desmoglein 3, the pemphigus vulgaris antigen.