Case Presentation: 38 year old male with history of rheumatoid arthritis presented to the emergency department with six months of episodic fever up to three times a week. Associated symptoms included occasional nonproductive cough and intermittent diffuse abdominal pain without any report of nausea, vomiting, or diarrhea. He denied any other localizing symptoms including dysuria or joint pain. He had been seen by his PCP for his fevers over this period of time with unrevealing workup. His only home medication was acetaminophen. Social history revealed that he had immigrated from Honduras six years ago but he denied any recent travel. Family history significant for father with rheumatoid arthritis.
He was febrile to 39.5C on arrival with otherwise normal vital signs. Physical exam was normal except for a diffusely tender abdomen. Labs significant for AST 113, ALT 101, CRP 239, ESR 30. All other labs were normal, including CBC and urinalysis. CT scan of chest/abdomen/pelvis noted multiple mildly prominent mesenteric and hilar lymph nodes and mildly prominent fluid-filled loops of small bowel which could be consistent with enteritis. Lymph nodes were too small to be biopsied per pulmonology.
He was stable and afebrile off antibiotics during his 3-day hospital stay with negative initial workup including quantiferon gold, flu, blood cultures, hepatitis panel, EBV, CMV, and ANA. Stool PCR was positive for astrovirus, which is self-limiting when infectious. However, he developed eosinophilia on his last two hospital days. His liver enzymes initially improved but increased up to AST/ALT in the 100s on his last two hospital days as well. He had an episode of diarrhea on the day of discharge; stool ova and parasite was positive for Strongyloides stercoralis larvae and he was treated for Strongyloidiasis.
Discussion: Strongyloides stercoralis is a helminth that can live its life cycle completely in the human host. Transmission usually occurs via soil or the fecal-oral route, and infection can be perpetuated through autoinfection. Larvae develop in the GI tract and can migrate to other organs, including the skin and lungs, prior to migrating back to the small intestine to become adults. Adult worms can live up to five years, burrowing in the mucosa of the small intestine.
Strongyloidiasis in immunocompetent individuals can be difficult to identify, as many patients are asymptomatic with eosinophilia being the only clue. Any symptoms are usually mild and nonspecific, and can include waxing and waning gastrointestinal (abdominal pain, diarrhea, nausea, vomiting), pulmonary (dry cough), or dermatologic symptoms (pruritis, urticarial).
In the workup of fever or unknown origin, eosinophilia can be a clue favoring helminthic infection or a drug reaction. In addition to medication review and reconciliation, testing for helminthic infection such as strongyloidiasis, ascariasis, and hookworm should be considered in appropriate populations.
Conclusions: Patients with Strongyloidiasis can have few, if any clinical symptoms. Often patients are asymptomatic with labwork showing eosinophilia. The presence of eosinophilia in a patient with fever of unknown origin should prompt workup for drug reaction or a helminthic infection such as strongyloidiasis, ascariasis, or hookworm.