| Abstract: | Background: Mastocytosis describes a heterogeneous group of disorders arising from a clonal proliferation of mast cells. Given the lack of curative treatments for the cutaneous form, there is a significant need for superior therapies. Omalizumab is a recombinant DNA‐derived humanized IgG monoclonal antibody that selectively binds to human immunoglobulin E (IgE). It represents a potential treatment for the management of cutaneous mastocytosis, which currently has no standard treatment. Methods: Two patients were treated with subcutaneous omalizumab 300 mg every 4 weeks. Discussion: Patient 1 experienced 50% reduction in cutaneous infiltration and moderate improvement in pruritus. Patient 2 underwent 90% complete clearance of cutaneous lesions and reported full resolution of pruritus. The median duration of treatment was 24 weeks and time to response was 8 weeks. No significant changes in tryptase levels were observed. Both patients experienced injection site reactions. Conclusion: We provide evidence from two cases supporting the efficacy of IgE‐mediated therapy in the treatment of cutaneous mastocytosis. Even at a higher‐than‐standard dose (300 mg vs. 150 mg), the drug was well‐tolerated. As we await the results of pivotal clinical trials, omalizumab appears to be a promising treatment option in patients with cutaneous mastocytosis unresponsive to traditional therapies. |
