Eosinophilic pustular folliculitis. Studies on possible chemotactic factors involved in the formation of pustules.

Eosinophilic pustular folliculitis (EPF) is a dermatosis of unknown aetiology, characterized by repeated development of pruritic follicular papulopustules with a tendency to form an annular configuration on the face and other seborrhoeic areas, and by palmoplantar pustular lesions in one-fifth of the patients. Both types of lesions are infiltrated mainly by eosinophils with some polymorphonuclear leukocytes (PMN). To elucidate the mechanisms underlying pustule formation, we studied the chemotactic activity for leukocytes of the skin surface lipids (SSL) obtained from seborrhoeic areas. No specific chemotactic activity was detectable in stored SSL from patients with EPF. However, fresh SSL collected from the seborrhoeic areas of normal adults contained chemotactic substances for eosinophils and PMN which were labile on storage in air. In stratum corneum extracts from palmoplantar lesions of patients with EPF we demonstrated the presence of a 13000 molecular weight chemoattractant factor for PMN, the activity of which was partially inhibited by antiserum against C5a, and a low molecular weight lipid-soluble chemotactic factor for eosinophils, the activity of which was also lost on storage in air. Our findings suggest that these chemotactic factors play a role in the production of the characteristic pustular lesions of EPF.