Intestinal Capillariasis Diagnosed by Endoscopic Biopsy
In June 2004, a 42-year-old male patient was admitted to our hospital with a nearly 2-year history of intractable diarrhea. He had been residing in the Philippines for 9 years before his visit. He was a fisherman, and he enjoyed eating raw fish. He experienced watery diarrhea several times daily during the last 2 years, with no significant impact on his daily life. However, the diarrhea unexpectedly worsened approximately 2 months before presentation, resulting in a weight loss of 10 kg. He was thus admitted to a hospital in the Philippines, but no improvement was observed. He subsequently returned to Korea for evaluation and treatment several days before admission to our hospital.\nOn presentation, he complained of symptoms including severe diarrhea, weight loss, and abdominal pain. Physical examination revealed stable vital signs with normal blood pressure and heart rate. Routine laboratory tests revealed leukocytosis with a white blood cell count of 16,550/mm3 but without eosinophilia, hyponatremia (sodium level, 128.5 mmol/L), hypokalemia (potassium level, 3.11 mmol/L), and hypoalbuminemia (albumin level, 1.2 g/dL). Further laboratory studies and colonoscopy were performed to rule out any medical conditions leading to chronic diarrhea. Results of the stool examination for parasites, acquired immune deficiency syndrome test, and antineutrophil cytoplasmic antibody test were negative. Thyroid function test showed a free thyroxine level of 1.27 ng/dL, a triiodothyronine level of 80.01 ng/dL, and a thyroid-stimulating hormone level of 3.94 µIU/mL, all within the reference range. Colonoscopy revealed no significant abnormal findings. Abdominopelvic computed tomography (AP CT) showed diffuse wall thickening of the small bowel with mesenteric lymph node enlargement. This was followed by a small bowel series to verify the presence of the lesion found in AP CT. A plain radiograph of the small bowel revealed straightening of the lumen, known as a ribbon-like appearance in the ileum, without abnormal disturbance of passage (). Although the folds of the jejunum were relatively spared, those and the villi of the ileum were obliterated, along with the luminal straightening. A second colonoscopy session was planned for the purpose of biopsy to detect mucosal lesions in the ileum that may be indicative of the cause of the diarrhea (). Although the second colonoscopy also failed to identify any striking anomaly in the mucosae of the terminal ileum and colon, endoscopic biopsy at the distal ileum was performed because of the suspicion of several diseases limited to the small intestine; this revealed chronic inflammation with mucosal atrophy, eosinophilic infiltration, and the presence of parasitic worms in the mucosa, consistent with intestinal capillariasis (). The diagnosis of intestinal capillariasis was confirmed, and the patient received 400 mg of albendazole daily for the next 4 weeks. At the end of 4 weeks, all of his symptoms abated, and he showed an increase in body weight from 48 to 58 kg. While stool examination, probably the simplest method of evaluating parasitic infestation, was performed as part of the initial examination, neither the larvae nor the ova of the parasite were observed. Thus, after the confirmation of C. philippinensis infection through a pathologic study, stool examination was repeated once before albendazole treatment and three times after medication to further validate the finding. Nevertheless, the result of stool examination was negative in all five occasions.