Refractory case of adrenergic urticaria successfully treated with clotiazepam

Adrenergic urticaria (AU) is a rare type of stress‐induced physical urticaria characterized by widespread pruritic urticarial papules. Diagnosis can be made by i.d. injection of adrenaline or noradrenaline, which produces the characteristic rash. Although the lesions of AU typically respond to beta‐blockers such as propranolol, the therapeutic options for AU are limited. Here, we report a case of AU that was resistant to beta‐blockers and successfully treated with clotiazepam. The clinical picture of AU resembles that of cholinergic urticaria (CU), however, positive noradrenaline test and negative acetylcholine skin test were useful for the differential diagnosis of AU and CU. Although his symptoms were resistant to several therapeutic methods including olopatadine (H₁ antagonist), lafutidine (H₂ antagonist) and propranolol, the severity and frequency of his attacks and his subjective symptoms were reduced by oral clotiazepam, an anxiolytic benzodiazepine. Dermatologists should be aware that anxiolytic benzodiazepines may be a therapeutic option in AU.