Eotaxin expression in Onchocerca volvulus-induced dermatitis after topicalapplication of diethylcarbamazine

In persons with onchocerciasis, topical application of the anthelminthic di ethylcarbamazine (DEC) induces clinical and histologic responses similar to acute papular onchodermatitis, including recruitment of eosinophils to the skin, To determine whether the eosinophil chemokine eotaxin is likely to b e associated with eosinophil recruitment in onchodermatitis, DEC was applie d to a 5-cm(2) area on the skin of infected persons, and biopsies were take n from lesions 24 h litter. Histologic analysis showed elevated dermal and epidermal eosinophils compared with tissue from an adjacent (untreated) sit e. Reverse transcription-polymerase chain reaction showed that eotaxin gene expression in DEC-treated skin was elevated 2- to 17-fold compared with co ntrol tissue. Eotaxin immunoreactivity was noted in mononuclear cells and e osinophils in the perivascular region of the dermis and in lymphatic and va scular endothelial cells. Together, these observations are consistent with a role for eotaxin in recruitment of eosinophils to the dermis in early sta ge onchocercal skin disease.