Fever and altered mental status in a psychiatric inpatient: Suspected concealed medication ingestion as a diagnostic lesson

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BSTRACT

Fever and altered mental status commonly prompt evaluation for infection, but noninfectious causes should be reconsidered when bedside findings are discordant. This is particularly important in patients with psychiatric illness, in whom history-taking and interpretation of physical symptoms may be challenging. A 22-year-old woman hospitalized for psychiatric management after a suicide attempt developed fever and impaired consciousness. Initial assessment revealed mydriasis, urinary retention, anhidrosis, patellar hyperreflexia, jaw clenching, leukocytosis, a low C-reactive protein level, and no clear infectious focus. Three unidentified tablets were found at the bedside. Infection and sepsis were initially considered because of fever, altered mental status, leukocytosis, and lactate elevation. However, the autonomic and neuromuscular findings were discordant with a typical infectious presentation, and suspected concealed medication ingestion with mixed toxidrome features was considered. She improved within 24 hours with supportive care. One month later, she reported ingesting 240 tablets of dextromethorphan. Toxicological confirmation, serum drug concentration measurement, and tablet identification were unavailable. In patients with psychiatric illness, fever and altered mental status should prompt evaluation for infection, but clinicians should also consider concealed medication ingestion when bedside findings are discordant. Mixed or incomplete toxidrome features should not exclude intoxication, and self-reported ingestion should be interpreted cautiously when objective confirmation is unavailable.