Increased concentration of platelet-derived chemokines in serum of patients with delayed pressure urticaria.

BACKGROUND Delayed pressure urticaria (DPU) is a distinct form of urticaria, characterized by marked dermal swelling, deep inflammatory infiltrate and systemic symptoms. Little is known about inflammatory mediators involved in this disease. OBJECTIVE To investigate secretion of platelet-specific chemokines, platelet factor 4 (PF-4) and beta-thromboglobulin (beta-TG) during the course of DPU. METHODS AND MATERIAL Plasma concentrations of PF-4 and beta-TG were measured in eight adult DPU patients and in 15, age- and sex-matched, healthy controls. RESULTS Plasma PF-4 and beta-TG concentration scores were significantly higher in the DPU group as compared with the control subjects. CONCLUSION The present study, as well as an earlier contribution, suggest that distinct platelet activity may be identified in different types of urticaria. In contrast to chronic idiopathic urticaria, chronic urticaria with a positive response to autologous serum skin testing, and acute urticaria, delayed pressure urticaria may be associated with increased secretion of platelet chemokines, similar to that observed in cold urticaria.