[Persistent pruritus after hydroxyethyl starch infusions. Retrospective long-term study of 266 cases].

In 266 patients receiving hydroxyethyl starch (HES) for otological indications, we retrospectively analysed the incidence of pruritus and its relationship to clinical and therapeutic parameters. We found that 32% of the patients developed pruritus, which characteristically appeared as pruritic crises. In 55% of pruritic patients onset after the HES medication had already been discontinued was reported. The symptoms persisted on average for 8.8 weeks. Pruritus was generalized, but with a predilection for the trunk and genitalia. Coincidental atopic disease or higher age did not promote pruritus. However, the incidence of pruritus correlated well with the cumulative dosage and also depended on the type and molecular weight of HES given (6% or 10%, mol.wt. 40 or 200 kDa). Light and electron microscopic assessment showed deposits of HES, especially within dermal macrophages and endothelial cells and adjacent to nerve fibres. Pathogenetically a histamine-independent pathway is probably responsible for the induction of pruritus. Hence, classic antihistaminic drugs had no therapeutic effect in our patients.