Tropical sprue (TS)
What is tropical sprue?
Tropical sprue is a syndrome of intestinal malabsorption of two or more substances (Vit B12 and folic acid def is very common) which occurs among residents in or visitors to certain regions of the tropics. It often follows an acute diarrhoeal illness.
It is generally considered to be a disease primarily of the proximal small intestine.
Discuss the aetiology of TS?
The cause has not been clearly defined. While no single identifiable pathogen has been isolated, it is believed that persistent overgrowth in the small intestine of coliform bacteria leads to small bowel structural damage and chronic diarrhea.
Discuss the clinical features of TS?
- It should be suspected in patients with chronic diarrhea who have lived for more than one month in an area where tropical sprue exists. The diarrhea can first develop after a patient returns from the tropics.
- It is syndrome of chronic diarrhoea often with clinical features of steatorrhea, anorexia, abdominal cramps, bloating and prominent bowel sounds. Lactose intolerance is common.
Discuss the diagnosis of TS?
- Exclude infections with infection with Giardia lamblia, cryptosporidium parvum, and Cyclospora cayetanensis. (Stool tests X3)
- Once specific causes of diarrhoea and malabsorption have been excluded, fat, vitamin B12 and possibly D-xylose malabsorption are established, and a jejunal biopsy shows partial villus atrophy, the diagnosis can be assumed to be tropical sprue.
Discuss the treatment of TS?
- Restoration of water and electrolyte balance and replacement of nutritional deficiencies. There is dramatic response to oral folate therapy, so that it is almost considered to be diagnostic of the illness. Folate therapy leads to return of appetite, weight gain and general sense of well being.
- However, despite folate therapy, clinical and morphologic abnormalities of the intestine persist in 50 percent of patients who reside in an endemic area in the tropics. The administration of sulfa drugs or tetracycline for three to six months completely reverses the intestinal and hematologic abnormalities of tropical sprue in a majority of patients.
So, tetracycline (250 mg PO four times daily) plus folic acid (5 mg/day) for three to six months is recommended as treatment for tropical sprue.
