Effect of high-dose intravenous immunoglobulin in delayed pressure urticaria

Background Delayed pressure urticaria (DPU) is difficult to treat. High-dose intravenous immunoglobulin (IVIG) has been found to be effective in treating patients with autoimmune chronic urticaria. Objectives To report the effect of IVIG on eight patients with severe unremitting DPU. Methods IVIG was administered at a dose of 2 g kg(-1) over 2-3 days on an in-patient basis. The response to treatment was assessed subjectively and recorded as remission, improved or unchanged. An autologous serum skin test (ASST) was performed in seven patients. Results Three of eight patients achieved remission; two after one infusion and one after three infusions. Two patients improved. Three patients remained unchanged; of these, two declined further treatment after two infusions, and one failed to improve after six infusions at monthly intervals. Four of seven patients had positive ASST; three responded to IVIG. Two developed delayed positive ASST; both responded to IVIG. Of three patients with negative ASST, two responded. Conclusions IVIG induced remission or improved symptoms in five of eight patients with DPU with severe unremitting disease who had failed to respond to other therapies or were controlled only with systemic corticosteroids. Those who responded did so with three or fewer infusions. ASST is not a reliable predictor of response to IVIG.