Lemierre syndrome caused by oral sex.

A 58-year-old man presented to the emergency department with a 2-week history of worsening bilateral neck pain. Persistent high fever and a restricted ability to open his mouth due to the neck pain caused feeding difficulties. His vital signs were as follows: blood pressure, 144/82 mmHg; respiratory rate, 20 breaths/minute; oxygen saturation on ambient air, 98%; and body temperature, 37.5 C. Results of a clinical examination revealed neck swelling, with warmth and redness, but skin eruption was not observed. Even a light touch caused severe neck pains, and he could not bend his own neck. Inspection of the oral cavity could not be completed due to the restricted ability to open the mouth. White blood cell count and C-reactive protein (CRP) level were 20,430 cells/mm and 31.42 mg/dL, respectively. Chest radiography (Fig. 1A) and contrast-enhanced neck computed tomography (CT) (Fig. 1B) on admission showed no major abnormalities. After administering sulbactam/ampicillin intravenously, the neck pain and fever gradually resolved, and the CRP levels decreased. Blood cultures tested positive for Fusobacterium sp. 5 days later. Confirmation of Lemierre syndrome (LS) revealed his sexual activity. He reported forcible oral sex with a male partner 2 days before the onset of neck pain. The oral cavity was examined when restriction of the mouth opening had subsided, but trauma or dental caries were not