Nocardia pneumonia

In this chest x-ray, there is diffuse, reticulonodular shadowing and bilateral hilar enlargement. The patient, who was HIV-positive, was treated empirically for Pneumocystis carinii pneumonia (PCP) with 3 weeks of co-trimoxazole and improved. (Hilar lymph node enlargement is not a feature of PCP.) The patient relapsed 6 weeks later and, at this stage, Nocardia asteroides was cultured, thus accounting for the clinical response to co-trimoxazole and subsequent relapse. The usual treatment for nocardia pneumonia would be 3 months or more on co-trimoxazole. Nocardia often mimics tuberculosis (TB) and may account for 10% of suspected tuberculosis cases in a population where HIV and TB co-infection is common.