Omalizumab for the Treatment of Solar Urticaria: Case Series and Systematic Review of the Literature

Solar urticaria (SU) is a rare photodermatosis causing a significant impact on patients' quality of life. Although the condition can be controlled with phototherapy and/or a combination therapy of antihistamines and leukotriene antagonist in most patients, a subset of patients require additional therapy with omalizumab; however, efficacy data are sparse. The objective of this study was to determine the efficacy and safety of omalizumab for treating SU. A case series of 5 patients with SU refractory to antihistamine and leukotriene antagonist combination who were treated with omalizumab is described. In addition, a systematic review of studies evaluating patients with SU treated with omalizumab was conducted. The primary outcome was partial/complete clinical response. Secondary outcomes were 10-fold decreases in the baseline minimal urticarial dose and adverse events. Our case series included 5 patients with SU. Monthly omalizumab doses of 150 to 600 mg resulted in clinical improvement in all patients and complete remission in 4. No adverse effects were reported. The systematic review included 22 studies (48 patients). All patients failed to control disease with antihistamines before omalizumab treatment. Patients received omalizumab at monthly doses of 150 to 750 mg over a follow-up period of 4 to 200 weeks. Thirty-eight patients (79%) experienced clinical improvement. Four patients (11%) had mild adverse effects. Omalizumab provided clinical benefits in approximately 80% of patients with SU. Patients failing to improve on standard omalizumab doses may benefit from higher monthly dosages.