The Painful Mouth and the Quiet Lungs

A 24-year-old woman is admitted with 6 days of fever, dry cough, malaise, and worsening oral pain. During the last 72 hours she has developed severe odynophagia, bleeding lip crusts, and inability to tolerate food or liquids. She reports pleuritic chest discomfort but no dyspnea.

Ten days before presentation, she completed trimethoprim-sulfamethoxazole for culture-confirmed Escherichia coli pyelonephritis, and her urinary symptoms resolved. She is sexually active with multiple male partners, returned from Acapulco 3 weeks ago, and has no history of recurrent oral ulcers, autoimmune disease, or chronic immunosuppression.

She appears uncomfortable and dehydrated. Temperature is 38.6 C, heart rate 108/min, blood pressure 104/68 mmHg, respiratory rate 18/min, and oxygen saturation 97% on room air. The lips have hemorrhagic crusting with shallow erosions of the buccal mucosa, tongue, and soft palate. A few targetoid papules and small vesiculobullous lesions are present on the upper trunk and forearms, involving less than 3% of body surface area. There is no epidermal detachment.

White blood cell count is 7.6 x 10^3/uL with an absolute lymphocyte count of 0.8 x 10^3/uL; creatinine is 0.9 mg/dL, AST 41 U/L, ALT 36 U/L, and C-reactive protein 54 mg/L. HIV antigen-antibody testing, rapid plasma reagin, oral herpes simplex virus polymerase chain reaction, respiratory viral panel, and blood cultures are negative. Chest radiograph shows faint patchy interstitial infiltrates.