Strongyloides stercoralis with Gastroduodenal Involvement and Complicated with SIADH: An Unusual Diagnosis to Consider in Immunosuppressed Patients with Hyperemesis and Eosinophilia

Abstract

<i>Strongyloides stercoralis</i> is an intestinal nematode that colonizes and reproduces in the upper small intestinal mucosa. Infection in immunocompetent hosts is self-limited but in immunocompromised patients it can be complicated and cause hyperinfection. We present a 60-year-old female who was admitted due to an exacerbation of acquired thrombotic thrombocytopenic purpura requiring high doses of corticosteroids. The patient began to experience persistent pyrosis, nausea, vomiting, and oral intolerance. She was di­agnosed with syndrome of inappropriate secretion of antidiuretic hormone (SIADH). Upper endoscopy was performed and showed esophageal, gastric, and duodenal mucosa with edema and erythema. Moreover, there were superficial erosions and thickened folds in duodenum. Gastric and duodenal biopsies were taken. Abdominal computed tomography and magnetic enteroresonance displayed duodenal dilation and inflammatory changes. The histological study of biopsies showed colonization by <i>S. stercolaris</i> in the antrum and duodenum. <i>S. stercolaris</i> is a human parasite that is endemic in tropical, subtropical, and temperate regions. Its lifecycle is complex because it completes its entire cycle within the human host; it penetrates the skin, migrates to the lungs, and reach the gastrointestinal tract. The most affected site is the duodenum and upper jejunum. The lifecycle includes autoinfection through the intestinal mucosa or perianal skin, especially in immunocompromised hosts. Immunossuppression can lead to hyperinfection syndrome and disseminated disease. However, involvement of the stomach has relatively rarely been reported. SIADH has been related to systemic hyperinfection, although the mechanism is not clear. The relatively nonspecific clinical and imaging features and the low sensitivity of routine parasite tests make the diagnosis challenging and delayed.