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 This can be withdrawn later if the patient starts HAART and the CD4 count remains consistently 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?

Malignancy

The incidence of Kaposi’s sarcoma (KS) has declined significantly since the widespread introduction of HAART. It is a vascular tumour that is associated with human herpes virus type 8 (HHV8). Although most commonly found on the skin, KS can infiltrate the lungs to cause cough and shortness of breath. On examination, other KS lesions are usually found on the skin or in the mouth, but in rare cases the lungs alone may be involved.

Radiological changes are of diffuse lung infiltration often with a nodular appearance. Pleural effusion might be present. Lesions are visualised on bronchosocopy. Treatment is with systemic chemotherapy. Anti-retroviral therapy should be initiated if the patient is not already on treatment.

Non-Hodgkin’s lymphoma can also cause lung infiltration. Patients additionally present with systemic ‘B’ symptoms. On examination lymphadenopathy and splenomegaly might be found. Hilar lymphadenopathy seen on the CXR and CT scan indicate widespread lymph node enlargement in the chest and abdominal cavities. The diagnosis is made on the histological appearance of lymph node biopsy. Such lymphomas are often aggressive. Treatment is with chemotherapy (see Kumar and Clark, Clinical Medicine 6th edn, p. 510).

How would you manage an HIV-positive patient with chest problems?

The differential diagnosis in an HIV-infected patient presenting with respiratory symptoms is wide. There is considerable advantage in establishing a specific diagnosis rather than treating symptoms empirically. Factors that impact on diagnosis and management include the clinical presentation, the level of immunosuppression of the individual, lifetime exposure to infective agents and current medication.

Assessment

Treatment

If the patient is clinically immunosuppressed, has a previous AIDS-defining illness or is known to have a CD4 count < 200/mm³ and has chest X-ray abnormalities or desaturates on exercise, or has a hypoxic blood gas picture suggestive of pneumocystis infection, institute therapy pending bronchoscopy. Organisms will still be found several days into treatment.

If the patient has a history of TB or of exposure to TB, or has clinical and radiological findings consistent with TB, isolate the patient and investigate. Do not initiate empirical anti-tuberculous therapy without an expert opinion, as this will have long-lasting and far-reaching consequences for the patient and for future management.

If the patient has sputum smear positive for AFB or has culture-proven TB, isolate and start anti-tuberculous therapy with four drugs. Notify and seek expert opinion.

If the patient has clinical or radiological signs of bacterial infection, institute therapy with broad-spectrum antibiotics, e.g. amoxicillin or azithromycin.