The Omalizumab is a humanized anti-IgE monoclonal for which the extensive experience of its use in allergic asthma confirms its very good tolerance. By frequent association with asthma, atopic dermatitis is the first dermatological field has having tested this biological agent, unfortunately without convincing study at present. Surprisingly, this anti-IgE antibody is also reported as effective in certain non-IgE-mediated diseases including several dermatological indications. Since 2014, the Omalizumab got the indication in Europe for the treatment of chronic spontaneous urticaria after escapement to antihistamines. It also seems promising for prevention of anaphylaxis in mastocytosis and some refractory bullous pemphigoid.