Anaphylaxis to Topically Applied Sodium Fusidate
A 16-year-old boy visited an outpatient clinic for further evaluation of anaphylaxis. He presented to the school nurse after acquiring abrasions on his arms during exercise. The nurse applied a topical ointment containing sodium fusidate to the abrasions. Within 30 minutes, the patient began experiencing eyelid swelling and urticaria with pruritus of his whole body. He then began coughing and had difficulty breathing. He was taken to the nearby hospital and received emergency treatment. Two years earlier, he had been brought to the emergency department with symptoms of urticaria, eyelid edema, a cough, and dyspnea after taking medications containing acetaminophen, tiropramide, domperidone, and trimebutine. However, drug allergy was not confirmed at that time. No past medical history of asthma or allergic rhinitis or family history of allergic diseases was found.\nWe performed an oral provocation test with 125 mg (1/2 tablet) of fusidic acid. Thirty minutes after the first dose, the patient presented with a cough and an itching sensation on his neck followed by chest discomfort and urticaria on the forehead and right arm. Forced expiratory volume in 1 second (FEV1) dropped from 4.09 L at baseline to 3.50 L after challenge, although wheezing was not heard in his chest. The provocation test was terminated and an inhaled bronchodilator was given using a nebulizer. Chest discomfort was relieved and FEV1 rose to 3.86 L following management. His skin lesions improved with oral administration of antihistamine. Oral provocation tests with acetaminophen, amoxicillin, and cefadroxil were all negative. However, he showed conjunctival injection and itchy throat 30 minutes after a challenge test with 100 mg tiropramide. His final diagnosis was drug allergy to fusidic acid and tiropramide. We recommended that these drugs should not be administered systemically and not to use topical fusidic acid on abrasions.