An 18-year-old woman presented with a 7-day history of fever up to 39.2 °C followed by painful oral enanthema. She had taken acetaminophen as a palliative medicine. Her past history was unremarkable. Physical examination showed hemorrhagic crusts and necrotic ulcers on the lips. Prominent swelling with dilated capillaries and white sloughs of the attached gingiva over the teeth were observed (A, B). Laboratory investigations were unremarkable, except for elevated C-reactive protein at 3.81 mg per deciliter (reference < 0.30). Serum anti-herpes simplex virus (HSV) IgM was positive, but IgG was negative. The Tzanck test was positive, and polymerase chain reaction detected HSV type 1 (HSV-1) DNA. Primary HSV-1-induced herpetic gingivostomatitis were diagnosed. She was treated with oral valacyclovir, and the lesion completely resolved in 10 days.

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Corresponding author
Sho Katayama, Department of Dermatology, Chitose City Hospital, Chitose, Japan (zsk.azure@gmail.com)