Infected patients can be asymptomatic or have intermittent symptoms. Patients are likely to complain of a pruritic rash, cough, shortness of breath, abdominal pain, nausea, and/or diarrhea.3,4 The rash, called larva currens, results when the larvae invade the perianal region. The rash typically spreads to the buttocks, groin, and inner thighs.3
Immunosuppressed patients are at a heightened risk. Two serious forms of strongyloidiasis—hyperinfection syndrome (HS) and disseminated strongyloidiasis (DS)—can develop in immunosuppressed individuals. This can occur in patients receiving high-dose corticosteroids.3-5 Immunosuppression can lead to accelerated autoinfection and a large burden of migrating larvae in the body.
HS was suspected in our patient based on her worsening lung disease, recent onset of diarrhea, and rash in the setting of increased eosinophils.
HS is usually limited to the pulmonary, GI, and skin systems, whereas DS can invade numerous other organs. Complications of HS and DS include disseminated bacterial and fungal infections; the mortality rate if either condition is left untreated is close to 90%.3-5
Strongyloidiasis can mimic other infections
The differential diagnosis for S. stercoralis infection includes the following:
Clostridium difficile infection must be excluded in a hospitalized patient with persistent diarrhea. A stool toxin and antigen test is used to make the diagnosis. Patients with C. difficile infection are more likely to have eosinopenia than eosinophilia.6
Schistosomiasis is a helminth infection that can also persist for decades. The signs and symptoms of a chronic infection can be similar to strongyloidiasis. However, patients with schistosomiasis will typically have large organ damage, bloody diarrhea, and/or urinary symptoms. Diagnosis is made from testing multiple stool samples, urine, and serology.6
Adrenal insufficiency occurs with complete or partial loss of endogenous glucocorticoids. There can be resultant eosinophilia, although it is usually not as marked as the eosinophilia observed in our patient. Adrenal insufficiency is diagnosed with an early morning serum cortisol test and a cosyntropin stimulation test.6