A 57-year-old man was admitted to our hospital with a four-week history of nonproductive cough and dyspnea. His past medical history was notable for type II diabetes mellitus, chronic kidney disease with a baseline creatinine of 1.3 mg/dL, and untreated HIV/AIDS, which had been diagnosed 20 years previously. Prior opportunistic infections included oral candidiasis and cryptococcal meningitis. He was allergic to sulfonamides and had been prescribed dapsone for PCP prophylaxis, but he was not taking it reliably. His most recent known CD4 count and HIV viral load, 11 months prior to admission, were 15 cells/uL and 148,582 copies/mL, respectively.
Four days prior to presenting to our emergency department, the patient was admitted to another hospital with the same symptoms of nonproductive cough and shortness of breath. Chest radiograph at that time showed diffuse micronodules, greater in the right lung (Figure 1). There, he was empirically treated for both community-acquired pneumonia and PCP with ceftriaxone, azithromycin, clindamycin, primaquine, and steroids. He was also given fluconazole for thrush. Unfortunately, he left that facility against medical advice after 48 hours. He took no further treatment before coming to our hospital two days later.
When he subsequently came to our emergency department complaining of ongoing shortness of breath and cough, temperature was 35.9 degree Celsius, heart rate 119 beats per minute, blood pressure 107/71 mmHg, respiratory rate 18 breaths per minute, and oxygen saturation 96% while breathing ambient air. He was ill-appearing with conjunctival pallor and oral thrush. The remainder of his physical examination was normal, including chest auscultation, which revealed good air movement without wheezing, rales, or rhonchi. Laboratory analysis was notable for white blood cell count of 6,200 cells/uL with 63% neutrophils, 19% lymphocytes, 13% monocytes, and 3% eosinophils, elevated lactate dehydrogenase of 385 u/L, and positive beta-D-glucan of 389 pg/mL (Table 1). Chest roentgenogram revealed diffuse micronodules with confluent areas of nodular opacities (Figure 2). On the basis of these findings, the patient was admitted to our medical service and treated empirically for community-acquired pneumonia with ceftriaxone and doxycycline, for thrush with fluconazole, and for PCP with clindamycin and primaquine.
On hospital day 2, the patient developed worsening shortness of breath with hypoxemia requiring supplemental oxygen. A noncontrast, volumetric chest CT scan (Figure 3) revealed diffuse micronodules with central cavitation and bronchial wall thickening, most suspicious for mycobacterial or fungal infection. Notably, there were no ground glass opacities. Based on this CT and the lack of ground glass opacities, the treating team discontinued PCP therapy, initiated tuberculosis treatment, and consulted the pulmonary service for assistance and consideration of bronchoscopy. The patient underwent bronchoscopy with bronchoalveolar lavage (BAL) and transbronchial biopsy the following day. Pathologic analysis of the transbronchial biopsy specimen demonstrated foamy exudates on hematoxylin and eosin- (H&E-) stained sections, and silver stain revealed Pneumocystis jirovecii-type fungal organisms confirming the diagnosis to be PCP (Figure 4). No concurrent infections were found on cultures or pathologic samples (Table 2). The patient was treated with three weeks of clindamycin, primaquine, and prednisone. He was discharged home on hospital day 10 without requiring supplemental oxygen and did well thereafter, with a resolution of radiographic abnormalities on imaging obtained four months later (Figure 5).