A 38-year-old HIV-positive man (CD4 count 42 cells/µL, not on ART) presents with 3 weeks of fever, night sweats, and progressive breathlessness. CXR shows bilateral perihilar ground-glass opacities. PaO2 on room air is 58 mmHg. Induced sputum silver stain is positive for cystic organisms. What is the preferred treatment, and what adjunctive therapy is indicated given the PaO2?

• A IV pentamidine; no corticosteroids needed
• B Atovaquone; corticosteroids contraindicated in HIV patients
• C Trimethoprim-sulfamethoxazole (TMP-SMX) plus adjunctive corticosteroids (prednisolone) because PaO2 < 70 mmHg ✓
• D TMP-SMX alone; corticosteroids only for bacterial pneumonia

Explanation

This is Pneumocystis jirovecii pneumonia (PCP) in a patient with advanced HIV. TMP-SMX is first-line treatment for 21 days. Adjunctive corticosteroids (prednisolone 40 mg BD tapering over 21 days) are indicated when PaO2 < 70 mmHg or A-a gradient > 35 mmHg, as they reduce inflammation-mediated hypoxaemia progression and mortality (established in National Institutes of Health-sponsored trials). Pentamidine is a second-line option for TMP-SMX intolerance.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.