Low-dose cyclosporin A in the treatment of severe chronic idiopathic urticaria.

In a limited number of severe chronic idiopathic urticaria (CIU) patients, low-dose cyclosporin A (CsA) treatment was found to be effective. This open study aimed to extend this clinical observation and determine the safety of treatment with CsA. In addition, it aimed to determine the prevalence and characteristics of the autologous serum skin test (AST) in such patients, and whether this test is affected by CsA treatment. Thirty-five patients who suffered from severe CIU (score 3), and who were followed for 6 months (using a clinical urticaria-severity score [range 0-3]) were divided into three groups: 19/35 were treated for 3 months with low-dose CsA, and thereafter followed for an additional 3 months; 6/35 dropped out of protocol treatment; and 10/35 untreated patients (followed for the same period) served as a disease controls. In the treated group, no side-effects were observed, and by the end of treatment, 13/19 (68%) patients were in full remission (score 0) and the remainder scored 1. In contrast, the 10 CsA-untreated patients scored 3 for the whole follow-up period of 6 months. Positive AST was found in 14/35 (40%) of patients, whereas none were detected in 20 healty control subjects. AST neither correlated with disease activity nor predicted response to treatment. This uncontrolled study shows that low-dose CsA is effective in treating CIU patients, and can be given safely for 3 months. However, CIU patients requiring initially high doses of glucocorticosteroids and with a long clinical history are less amenable to CsA treatment.