Young Woman With Abdominal Pain, Eosinophilia, and Ascites
A 20-year-old woman presents with lower abdominal pain of 9 months’ duration. The pain is bilateral in the lower quadrants, dull, constant, and nonradiating. No factors aggravate or relieve the pain. She has had night sweats for 2 months and increased abdominal girth for 1 month, and she has lost an unknown amount of weight.
The patient is a Gambian immigrant; she has been in the United States for 2 years. She denies nausea, vomiting, diarrhea, dysuria, fever, and abnormal vaginal discharge. Her last menses was 3 weeks earlier. She has no significant medical or surgical history and is not taking any medication.
Vital signs and head and neck, cardiovascular, and lung findings are normal. No lymphadenopathy is noted. The abdomen is diffusely distended, with shifting dullness and fluid thrill; there is no hepatosplenomegaly. No tenderness, guarding, or rigidity is noted. Musculoskeletal findings are normal.
A complete blood cell count reveals a normal total white blood cell (WBC) count, with eosinophilic leukocytosis. The erythrocyte sedimentation rate; results of urinalysis, cultures of stool for ova and parasites, and liver function tests; and serum levels of electrolytes, blood urea nitrogen, and creatinine are all normal. A urine pregnancy test is negative.
A chest radiograph is unremarkable. CT scans of the abdomen and pelvis reveal a significant amount of free fluid (Figure 1). There is no evidence of portal hypertension. The adnexa are unremarkable. Paracentesis reveals bloody fluid, with 23,000 red blood cells per microliter and 21 WBCs per microliter (34% neutrophils, 52% lymphocytes, 7% monocytes, and 7% eosinophils). The serum-ascites albumin gradient is less than 1.1 g/dL.
Figure 1. CT scans of the abdomen and pelvis show ascites—a manifestation of chronic schistosomiasis.
Results of a peritoneal biopsy reveal fibrosis, mild chronic inflammation, and calcified structures that are strongly suggestive of Schistosoma eggs (Figure 2). Serologic test results are sent to the CDC. Enzyme-linked immunosorbent assay (ELISA) is positive for Schistosoma mansoni. However, an immunoblot assay is positive for Schistosoma haematobium and negative for S mansoni, which is interpreted as S haematobium infection. The immunoblot assay has a higher specificity than ELISA because it uses species-specific antigens; it is considered the confirmatory test. Calcification causes difficulties during mounting of the specimen and does not permit species identification based on morphologic criteria.