Methotrexate in autoimmune urticaria.

Sir, Chronic idiopathic urticaria may be autoimmune in origin (autoimmune urticaria), caused by functional autoantibodies that activate mast cells and basophils through cross linking the high affinity IgE receptor (FcεRIα) to secrete histamine. An incidence of 30% to 50% has been reported by various investigators. While there are no clinical features that distinguish ordinary urticaria from autoimmune urticaria, a simple test, the autologous serum skin test, can be used to detect functional autoantibodies. Patients with autoimmune urticaria whose disease is pursuing a severe disabling and recalcitrant course have been treated with immunosuppressive therapy, including cyclosporine. However, its high cost makes this drug an impractical option in India. Gach et al successfully tried methotrexate in two patients without detectable autoantibodies and in whom steroids and antihistamines were not effective. However, there are no randomized controlled studies of the use of methotrexate in patients with autoimmune urticaria. We report our preliminary experience of using methotrexate in four patients with autoimmune urticaria.