Hydroxyethyl starch-induced pruritus: clinical characteristics and influence of dose, molecular weight and substitution.

Severe persistent pruritus is a common, but incompletely characterized, complication of hydroxyethyl starch (HES) infusion. This retrospective study aimed to assess HES-induced pruritus by electron microscopic findings, pruritus characteristics, and response to stimuli, and to determine the impact of HES dosage, molecular weight and substitution. Seventy patients with electron micro-scopy-proven HES-induced pruritus were included. HES-laden vacuoles were observed in skin macrophages of all patients. The median latency between HES exposure and pruritus onset was 3 weeks, and the median duration of pruritus was 6 months. Pruritus was severe, or very severe, in 80% of patients. Mechanical stimuli triggered pruritus in 74% of patients. Although the median cumulative dose of HES was 300 g, 15% of patients developed pruritus after only 30 g. There were no significant differences between HES 130/0.4 and HES 200/0.5 in pruritus latency, duration or severity. HES-induced pruritus thus may occur at any dose, molecular weight or substitution.