New Onset of Alcohol Flushing in an Atopic Dermatitis Patient Treated with Dupilumab.

: Dupilumab is a monoclonal antibody that targets the alpha subunit of the interleukin-4 receptor. It has been used as an effective treatment for moderate to severe atopic dermatitis (AD) patients 1 . The adverse events include conjunctivitis, herpes simplex virus infection, and injection site reaction in varying proportions 1 . A 20-year-old male patient visited our hospital with pruritic erythematous plaques on the entire body from childhood. Based on the clinical findings, AD was diagnosed, and treatment with cyclosporine 100~200 mg was prescribed for more than one year. Because the cyclosporine treatment had not been effective, dupilumab administration was initiated. Subsequently, the patient’s clinical symptoms improved rapidly; however, after several months, he complained of facial flushing within a few minutes of consuming small amounts of alcohol (Fig. 1). He complained that this symptom lasted for less than one hour and had never occurred before treatment with dupilumab. No medications or topical agents were being taken concurrently. We considered the flushing in this patient as a rare adverse event that could occur after treatment with dupilumab, and the patient was educated to avoid alcohol consumption during the post-treatment period. Flushing is a transient erythema that most commonly occurs in the face because of an increase in cutaneous blood flow following vasodilation. One of the causes is the use of vasoactive substances, which include medication, food, and alcohol 2 . Alcohol flushing is caused by an increase in the acetaldehyde level due to deficiency or inactivity of aldehyde dehydrogenase 2 (ALDH2), which plays a major role in alcohol metabolism