Erythema marginatum and hereditary angioedema.

OBJECTIVE

To search for anaphylatoxin activity in plasma during episodes of erythema marginatum, and to evaluate the histology of erythema marginatum by electron microscopy and immunohistologic techniques.

METHODS

Plasma samples were studied for C5a activity by granulocyte aggregation, and C3 conversion by immunoelectrophoresis. A skin biopsy of erythema marginatum was done, and the tissue stained with a rabbit antibody to bradykinin.

RESULTS

No plasma anaphylatoxin was found. Dense deposits of bradykinin were discovered in stromal tissue and lining endothelial cells.

CONCLUSIONS

Bradykinin may be important in the causality of the erythema marginatum associated with hereditary angioedema.