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Histoplasmosis Manifests After Decades

Are immunocompromised patients ever out of the woods after the original health issue is resolved? A new study suggests not.


 

Immunocompromised patients can be at risk for complications long after the original health issue was resolved—a problem illustrated by a patient who had a heart transplant in 1986 but developed acute progressive disseminated histoplasmosis decades later.

The patient presented with altered mental status; a Mini-Mental State Exam showed confusion. A computed tomography scan of the patient’s head revealed lesions, raising the suspicion of metastatic malignancy, which was ruled out after biopsy of a medial right temporal brain lesion. MRIs of his chest, abdomen, and pelvis revealed bilateral masses on his adrenal glands. Guided adrenal biopsy showed necrotizing granulomas consistent with a diagnosis of disseminated histoplasmosis.

However, that diagnosis was questioned—the patient had lived in Arizona for years, not, for instance, the Midwest, where histoplasmosis is more common. Nor did he have a history of spelunking, prior exposure to bird or bat droppings. He did report a short visit to North Carolina 30 years earlier. And he had been on immunosuppressive drugs for years.

The patient was started on liposomal amphotericin B, which was discontinued when his renal function deteriorated. He was switched to itraconazole, then restarted on amphotericin B with close monitoring after the diagnosis was confirmed. His doses of immunosuppressive drugs were reduced.

The clinicians note that HIV/AIDS and use of immunosuppressive drugs are among the risk factors for disseminated infection. They cite 1 study that found immunosuppression was the single most common risk factor. In another study, the risk of histoplasmosis increased as CD4+ T cells dropped below 300/µL.

The patient’s case was complicated by the fact that it was > 30 years after his heart transplant, and he had made only a short visit to an endemic area. He also had no history of histoplasmosis—the clinicians say a database search turned up the fact that most reported cases were preceded by symptomatic infection.

When charting patient history, they advise placing emphasis on a history of travel to endemic areas and considering histoplasmosis in immunocompromised patients in nonendemic areas.

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