A Unique Case of Cryptococcus and Histoplasmosis Co-infection in an HIV-negative Male on Chronic Steroid Therapy

Histoplasmosis and cryptococcosis are systemic fungal diseases frequently encountered in immunocompromised hosts, particularly in patients with HIV/AIDS with low CD4 counts. However, co-infection with histoplasmosis and cryptococcosis is an uncommon clinical scenario, hence carrying the risk of under diagnosis by medical professionals. For instance, when one infection is identified, most health professionals will have a low suspicion for an additional co-infection. Here, we report the case of a 71-year-old gentleman with a new diagnosis of myasthenia gravis (MG) requiring recent steroid therapy who presented with recurrent respiratory symptoms despite treatment for community acquired pneumonia. Bronchoscopy and bronchoalveolar lavage (BAL) were performed; BAL samples revealed presence of Cryptococcus neoformans and histoplasma antigen (Ag). Serum cryptococcal Ag and urine histoplasma Ag returned positive as well. The patient then required inpatient treatment with amphotericin B, with eventual transition to oral fluconazole at discharge. Pulmonology and Infectious disease consults assisted in appropriate diagnosis and management of this rare presentation. Given the high prevalence of immunocompromised states in a myriad of medical co-morbidities, it is important to highlight this case to create awareness regarding possibility of concomitant systemic fungal diseases.