Chronic inducible urticaria (CIndU) is a subgroup of chronic urticaria which can cause severe quality of life impairment by their refractory forms. The recommended treatment approach in CindU is the same as that for chronic spontaneous urticaria (CSU). However, CIndU seem to be more resistant to standard doses of H1 antihistamines (AHs) and higher doses of AHs are required for symptom control. Omalizumab, a recombinant anti-IgE antibody, effectively treats CSU. Nevertheless, there is not enough evidence in patients with CIndU, especially in AHs resistant cases. This study analyzed 2 severe cases of CIndU (cold urticaria and symptomatic dermographism) with completely different response to omalizumab. We describe 2 patients with 2 subtypes of CIndU: one with severe cold urticaria (including anaphylaxis) and the other with severe extensive symptomatic dermographysm. In both cases, we performed complete positive and differential diagnostic work-up. Management strategies included first line and second line symptomatic therapy, but with no success in either case. Avoidance of eliciting triggers was difficult to achieve (occupational reasons). We decided to start omalizumab treatment, 300 mg every 4 weeks for 6 months. The cold urticaria patient gained complete symptom relief 10 days after the first dose of omalizumab; the quality of life improved substantially with no side effects of the treatment. The urticaria factitia patient showed no benefit of the add-on 5 months treatment with omalizumab. He refused the 6th dose of omalizumab due to the lack of response, and also cyclosporine, but he showed some benefits of oral corticosteroids. Although many clinical studies support the use of omalizumab in the treatment of patients with CIndU, we certainly need more data for prediction of a good clinical response.
Keywords: cold urticaria; inducible urticaria; omalizumab; symptomatic dermographysm.