Evidence for eosinophil degranulation in the pathogenesis of herpes gestationis.

Herpes gestationis is a pregnancy-related bullous dermatosis of unknown origin with associated tissue and peripheral blood eosinophilia. In this report, eosinophil degranulation in herpes gestationis was studied, and the role that the eosinophil may have as an effector cell that induces tissue damage through deposition of toxic cationic proteins is discussed. Using indirect immunofluorescence with antibody to human eosinophil granule major basic protein, major basic protein was observed both within tissue eosinophils and deposited extracellularly outside eosinophils in the dermis of eight patients with herpes gestationis. Possible mechanisms whereby eosinophils might be activated to degranulate in herpes gestationis are reviewed.