Efficacy and tolerability of cyclosporine microemulsion in chronic idiopathic urticaria. An Italian multicentre collaborative study

I Chronic idiopathic urticaria (CIU) is the most frequent form of urticaria, accounting for 70-80% of the cases (1). CIU is defined as a 6-week or longer history of urticaria in the absence of detectable physical, allergic, vasculitic, infectious or drug-induced causes (2). The presence of autoantibodies directed toward IgE or to the high-affinity IgE Fc receptor, detected by intradermal test with autologous serum, has been reported in approximately 30% of patients with CIU (3). A substantial proportion of patients with chronic urticaria and positive autologous serum skin test (ASST) could be recognized as an autoimmune urticaria autoreactive subgroup. Symptomatic treatment with antihistamines is the first choice for CIU but these drugs are not always effective. When symptoms are severe, corticosteroids are com-