An 18-month-old girl presented with a maculopapular rash 10 days after carbamazepine treatment. Initially, she was suspected of having a viral rash owing to associated fever. She deteriorated rapidly and was suspected of having anticonvulsant hypersensitivity syndrome or Stevens-Johnson syndrome. She developed features compatible with toxic epidermal necrolysis rapidly over 24 to 36 hours. Carbamazepine was then stopped. She responded immediately to high-dose intravenous pulse methylprednisone treatment. We discuss the controversy in the management of anticonvulsant hypersensitivity syndrome, toxic epidermal necrolysis, or Stevens-Johnson syndrome with high-dose corticosteroids, intravenous immunoglobulin, and antibiotics.