A 53-year-old woman with a history of rheumatoid arthritis and amiodarone-induced lung injury on immunosuppression presented with acutely progressive hypoxic respiratory failure and hypotension, found to have a serpiginous truncal rash, acute anemia, and elevated beta-d-glucan.
In this episode, we revisit the schemas for fever and rash (which highlights first addressing the life-threatening causes) and diffuse alveolar hemorrhage (which focuses on differentiating vasculitis from other etiologies).
The patient underwent bronchoscopy with bronchoalveolar lavage fluid demonstrating elevated leukocytes with a neutrophilic predominance as well as progressively bloody fluid, consistent with diffuse alveolar hemorrhage. Silver stain was diagnostic for Pneumocystis jiroveci, and pathology revealed helminthic larvae consistent with Strongyloides stercoralis. The patient was diagnosed with both Pneumocystis pneumonia and Strongyloides hyperinfection syndrome!
- Beta-D-glucan(BDG) is a cell wall polysaccharide found in many fungal organisms (with notable exceptions including Cryptococcus, the zygomycetes, and Blastomyces dermatitidis) and is frequently used as a laboratory marker for invasive fungal infections. Caution is advised when interpreting this test, as it is imperfectly sensitive and false positives have been reported in association with certain hemodialysis filters, immunoglobulins (e.g., IVIG), albumin, and beta-lactam antimicrobials (thought to be more of an issue with older formulations).
- Strongyloides stercoralisis an important human pathogen in tropical and subtropical areas throughout the world. While many cases of chronic strongyloidiasis are mild and may go unrecognized, severe manifestations can include the strongyloides hyperinfection syndrome and disseminated strongyloidiasis. Hyperinfection occurs when there is accelerated autoinfection (i.e., the ability to complete the parasitic life cycle entirely within the host – a trait relatively unique to Strongyloides among human helminthiases) and most commonly occurs in the setting of immune dysregulation or exogenous immunosuppression.
- Pneumocystis jiroveciis an important opportunistic infection in immunosuppressed patients. Originally identified by Carlos Chagasin 1909, who believed it to represent a pulmonary manifestation of the parasite Trypanosoma cruzi, it was later reclassified as a fungus in 1988. The most frequent symptoms include subacute dyspnea, nonproductive cough, and low-grade fever, with hypoxemic respiratory failure being the most common manifestation of severe decompensation.