RESUMEN
INTRODUCTION: Beta-blockers involve a group of drugs widely used nowadays. Propranolol was the first beta-blocker available in the market. It is the most prescribed first-generation betablocker and is commonly used. Beta-blocker allergy is extremely unusual. Only an isolated case of an urticaria reaction to propranolol has been published in 1975. CASE PRESENTATION: We present a 44-year-old man. In 2016, he was treated with a daily dose of 5 mg of propranolol prescribed for a diagnosis of essential tremor. On the third day of medical treatment, he experienced an episode of generalized urticaria directly related to the administration of propranolol. He continued with his habitual treatment and he had no other urticaria episodes. A drug provocation test was carried out with gradually increasing doses of the culprit drug. Thirty minutes after a total cumulative dose of 5 mg, the patient had several hives on the chest, abdominal region and arms. Two weeks later, a new drug provocation test was performed to bisoprolol as an alternative beta-blocker, with good tolerance. CONCLUSION: We describe a new case of urticaria secondary to propranolol, presenting as an immediate hypersensitivity reaction. Bisoprolol has been succesfully proved to be a safe option. Bisoprolol is a second-generation beta-blocker, it is available and commercialized worldwide, which makes it a good alternative.