A 55-year-old man with COVID-19 pneumonia is on day 12 of illness. He has been on dexamethasone 6 mg daily for 10 days. His oxygen requirement has decreased from 15 L/min to 4 L/min via nasal cannula. Inflammatory markers show CRP 18 mg/L (was 120 mg/L). He has new-onset confusion and agitation. What is the most likely cause?
- A COVID-19-associated encephalitis
- B Dexamethasone-induced psychosis ✓
- C Hypoxic brain injury from prolonged hypoxemia
- D Bacterial meningitis
Correct answer: B. Dexamethasone-induced psychosis
Explanation
Corticosteroid-induced neuropsychiatric effects, including confusion, agitation, and psychosis, are well-documented with dexamethasone, particularly in the second week of therapy. The improving CRP and decreasing oxygen requirement argue against ongoing severe COVID-19 encephalitis. Hypoxic brain injury would present earlier during the hypoxemic phase. Bacterial meningitis would present with fever, headache, and meningismus, not isolated confusion with improving systemic markers.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.