Dramatic improvement with colchicine in antihistamine- and omalizumab-resistant chronic spontaneous urticaria.

Chronic spontaneous urticaria (CSU) is defined as the presence of recurrent urticaria, angioedema or both without any specific triggers, which persists for ≥ 6 weeks. Refractory cases to standard therapeutic regimens including antihistamines, immunosuppressants and biologics have been reported. Therefore, it is crucial to evolve novel therapeutic strategies through accumulating refractory CSU cases, which are successfully treated. We here report a refractory case of CSU to antihistamines and omalizumab, which was dramatically improved with colchicine.