Solar Urticaria

Purpose of Review: Solar urticaria (SU) is a rare photodermatosis, characterized by an abrupt onset of urticaria lesions appearing within minutes of light exposure. The disease may have a significant impact on patients’ quality of life. This review provides an overview of SU, with attention to pathogenesis, workup, differential diagnosis, and treatment. Additionally, we present our stepwise therapeutic approach. Recent Findings: Treatment with omalizumab, a recombinant humanized anti-IgE antibody used as a third line treatment for SU, was shown to be beneficial in 80% of patients with antihistamine refractory disease, with 50% becoming symptom free. Summary: Accurate history taking and performance of photoprovocation establish a diagnosis of SU. Determining the relevant action spectrum and minimal urticaria dose are important tools for the management of patients. In patients with isolated UVB sensitivity, broad-spectrum sunscreens may be efficacious. In others, UV hardening and antihistamines constitute first-line treatment. Omalizumab is probably the most appropriate treatment in patients with antihistamine refractory disease.