Rituximab as Treatment of Chronic Idiopathic Urticaria

Abstract

Conventional treatment of chronic idiopathic urticaria involves high doses of antihistamines followed by omalizumab in refractory cases, however, there are patients who do not achieve resolution of symptoms despite both of these therapies. The following case series describes two cases of chronic idiopathic urticaria successfully treated with rituximab. The first patient is a 43 year-old woman with psoriatic arthritis and autoimmune thyroiditis who presented to us with chronic idiopathic urticaria. She was found to have elevated levels of anti-IgE receptor antibodies with levels greater than maximum level of detection. She was unresponsive to high doses of antihistamines, cyclosporine, prednisone, dapsone, mycophenolate mofetil, hydroxychloroquine, and omalizumab and ultimately trialed on rituximab with complete resolution of urticaria. Our second patient is a 49 year-old woman with multiple sclerosis, allergic rhinitis, and atopic dermatitis who was referred with humoral immunodeficiency. She was diagnosed with common variable immune deficiency and started on SQ immune globulin therapy. She also had long-standing generalized urticaria refractory to antihistamines which responded to rituximab started by her neurologist for a flare of her multiple sclerosis. Use of rituximab in treatment of chronic idiopathic urticaria is not well documented in literature today and should be entertained as possible therapy for cases of treatment-resistant chronic urticaria, especially in the setting of other autoimmune conditions.