A twenty-eight-year-old male patient with five-day’s fever (the highest body tempreture reached 39.4℃) and 10-hour’s rash (first on face) presented to the department of emergency for “drug rash”, at that time his temperature was 38.6℃. Two hours later, his temperature fell to normal. Then this patient’s entire body rash increased signiifcantly and lasted for 13 hours. Serum measles antibody IgM(+) conifrmed the measles diagnosis. He had received measles vaccine as a baby. Clinicians should be aware of this atypical clinical manifestation of adult measles. If this kind of patients were misdiagnosed as drug rash and given corticosteroid, measles disease may be aggravated. Speciifc serum measles antibody testing may be the only reliable method for differential diagnosis, but the earliest time point for examining the antibodies of measles still needs precise research.