A Case of Incontinentia Pigmenti

—An Electron Microscopic Observation of Eosinophils in the Epidermis—

Abstract

A case of incontinentia pigmenti was reported. The patient was a 20-day-old girl who immediately after birth began to show signs of erythema, vesicles and pustules in a linear arrangement on the extremities and trunk. Intensive blood eosinophilia was noted. The titre of 1:32 for cytomegalovirus was discovered at age 13 months. There were no other untoward findings. Electron microscopic examination of inflammatory skin lesion revealed spongiosis and vacuolar degeneration of keratinocytes. Numerous eosinophils with degranulating change were noted within the widened intercellular spaces of the epidermis. At the vicinity of those eosinophils, degenerative changes were prominent, and the cell debris was extensive. Some of them contained melanosomes. Those findings suggest that cytotoxicity of basic proteins and some hydrolases of eosinophils play an important role in the removal of the damaged cells and tissues. The cytotoxicity seems to facilitate the phagocytosis by macrophages.