What are the likely diagnoses and the immediate management?

Pneumocystis jiroveci pneumonia commonly has an insidious onset, often with worsening shortness of breath and deteriorating exercise tolerance; the cough is usually non-productive.

The introduction of highly active anti-retroviral therapy (HAART) in HIV-infected people has led to a significant decline in pneumocystis and the infection is now most commonly seen in those not previously recognised as HIV infected. Pneumocystis infection occurs most frequently in the context of significant immunosuppression, when the CD4 count is < 200 cells/mm³. There may be clinical markers of poor immune function, such as candidiasis, as in this patient.

Primary prophylaxis (cotrimoxazole is first line) is recommended in those who are aware of their HIV status if their CD4 count falls into this range. This intervention alone has reduced the incidence of pneumocystis infection in HIV-infected populations. Pneumocystis pneumonia is an AIDS-defining diagnosis.

How would you treat this patient?

IV cotrimoxazole (trimethoprim 15 mg/kg/day + sulfamethoxazole 75 mg/kg/day) is the preferred first-line treatment, although a significant proportion of patients will develop allergy. IV pentamidine or dapsone plus pyramethamine are also used.

Treatment is given for 3 weeks. Systemic corticosteroids (IV methylprednisolone 40 mg × 4 daily for 5 days) are added in severe cases (PO₂ less than 8 kPa). Patients with pneumocystis infection can develop respiratory failure and require ventilatory support. Pneumothorax is a further complication of pneumocystis.

The organism is not cleared by treatment and secondary prophylaxis (usually cotrimoxazole) is recommended. This can be withdrawn later if the patient starts HAART and the CD4 count remains consistently > 200 cells/mm³.

In a patient not already on HAART, initiation of therapy should be discussed with a specialist physician.

What other chest conditions are associated with HIV?