Synopsis
Recognise Pneumocystis pneumonia across HIV and non-HIV immunosuppression, combine oxygen assessment with organism detection, start weight-based co-trimoxazole promptly, add corticosteroids only for supported hypoxaemic indications, and prevent recurrence.
- Pneumocystis jirovecii pneumonia is an opportunistic fungal pneumonia associated with advanced HIV, prolonged corticosteroids, haematological malignancy, transplantation and selected immune-modulating therapies.
- HIV-associated disease often evolves over weeks with dry cough, fever and exertional breathlessness; non-HIV disease may progress rapidly with more severe hypoxaemia and fewer organisms.
- First-line imaging is chest radiography followed by CT when suspicion persists; bilateral diffuse ground-glass opacity is typical but not specific.
Key red flags
Resting hypoxaemia, rapid oxygen escalation, marked exertional desaturation, severe tachypnoea or respiratory fatigue requires urgent critical-care assessment.
Progressive exertional dyspnoea, dry cough, fever, fatigue and weight loss develop over days to weeks, with initially subtle examination findings.
Investigation priorities
Grade severity and determine need for corticosteroid and critical-care escalation.
Identify diffuse pneumonitis and complications while evaluating alternative diagnoses.
Management branches
An immunocompromised patient develops progressive dry cough, fever, dyspnoea or unexplained oxygen impairment.
- Use ABCDE, measure resting and exertional oxygen saturation, obtain a room-air arterial blood gas where safe, and involve critical care for escalating oxygen or fatigue.
- Obtain chest radiography and urgent thin-section CT when the film is normal or non-diagnostic but clinical suspicion remains high.
PJP is confirmed or strongly suspected and treatment cannot safely await final molecular results.