A 28-year-old HIV-positive patient (CD4 180 cells/μL) presents with progressive dyspnoea, dry cough, and low-grade fever. CXR shows bilateral perihilar interstitial infiltrates. SpO2 is 86% on room air. LDH is elevated. The MOST likely diagnosis and MOST important adjunct therapy is:

• A Bacterial pneumonia; add oseltamivir
• B Disseminated TB; start HRZE
• C Pneumocystis jirovecii pneumonia (PJP); add adjunctive corticosteroids (prednisolone) ✓
• D CMV pneumonitis; add ganciclovir

Explanation

PJP (formerly PCP) classically presents in advanced HIV (CD4 <200) with insidious dry cough, exertional dyspnoea, bilateral interstitial infiltrates, and elevated LDH. Treatment is high-dose TMP-SMX (21 days). Adjunctive corticosteroids (prednisolone) are indicated when PaO2 <70 mmHg or A-a gradient >35 mmHg (this patient's SpO2 86% meets criteria), as they reduce inflammation and mortality. CMV pneumonitis is less common. Bacterial pneumonia and TB present differently and LDH elevation is more typical of PJP.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.