Abstract
Omalizumab is an anti-immunoglobulin E (IgE) therapy indicated for moderate to severe persistent asthma and chronic spontaneous or idiopathic urticaria, with several other potential uses in dermatology. It is a recombinant, 95% humanized monoclonal antibody that selectively binds circulating human IgE, thereby reducing circulating IgE levels and inhibiting mast cell response to antigenic stimuli. It is approved for use in dermatology as a third-line and fourth-line treatment for chronic spontaneous urticaria in Europe and the United States, respectively. It has also demonstrated benefit off-label for several other dermatologic conditions, including physical urticarias, urticarial vasculitis, angioedema, atopic dermatitis, bullous pemphigoid, and mastocytosis. Adverse events associated with omalizumab are overall mild, with the most common reactions including nausea, nasopharyngitis, sinusitis, upper respiratory infection, arthralgia, headache, and cough. Anaphylaxis was reported during clinical trials for asthma, with an incidence of 0.1–0.2%, and, therefore, a black box warning for anaphylaxis from omalizumab exists. In the dermatology literature, only two patients have been reported to have anaphylaxis during treatment with omalizumab. Omalizumab is contraindicated in patients with severe hypersensitivity reaction to omalizumab or any of its ingredients and is pregnancy category B.