Acute hemorrhagic edema of infancy (AHEI)--a variant of Henoch-Schönlein purpura or a distinct clinical entity?

Acute hemorrhagic edema of infancy (AHEI) is an acute cutaneous leukocytoclastic vasculitis (LCV) of infants. The clinical picture has a violent onset with a short benign course followed by spontaneous complete recovery. We report 12 infants with AHEI who were studied clinically, serologically, and immunohistologically. Edema and palpable purpuric skin lesions were present in all infants who were in good general condition. Serologic studies were unremarkable. Light microscopic examination of the skin biopsy specimens revealed LCV as in Henoch-Schönlein purpura (HSP). Direct immunofluorescent study revealed depositions of various immunoreactants, including fibrinogen, C3, IgG, IgM, IgA, and IgE (100%, 100%, 22%, 78%, 33%, and 33%, respectively) in the wall and around the small vessels. Similar deposition of Clq was also present in three infants in whom Clq could be studied (100%). The clinical similarities and differences between AHEI and HSP have been discussed in the literature. AHEI is observed before 2 years of age and is confined to the skin. The skin lesions of HSP are more polymorphic. Although histopathologic findings are similar, the immunohistologic pattern found in our series of AHEI is rather different from the pattern of HSP. Taking all of these findings into account, we suggest that AHEI should be considered as a separate, clinicopathologic entity or a possible variant of HSP. The more descriptive term "acute benign cutaneous LCV of infancy" is offered for this clinicopathologic entity.