Tropical sprue

Tropical sprue is a rare disorder of unknown cause affecting people living in tropical and subtropical areas who develop abnormalities of the lining of the small intestine, leading to malabsorption and deficiencies of many nutrients.

• • The cause is unknown, but infection is suspected.
  • Typical symptoms include anemia, light-colored stools, chronic diarrhea, and weight loss.
  • A doctor bases the diagnosis on symptoms in a person who lives in or has recently visited one of the areas in which the disorder commonly occurs.
  • The antibiotic tetracycline treats the disorder.

Tropical sprue occurs chiefly in the Caribbean, southern India, and Southeast Asia. Both natives and visitors (who spend at least 1 month in the area) may develop the disease, but children are rarely affected. This disorder has rarely been reported in the United States. Worldwide, its occurrence has been declining in recent decades. The cause is unknown, but available evidence suggests an infectious cause.

Symptoms

Light-colored, soft, bulky, greasy, and unusually foul-smelling stool (called steatorrhea), chronic diarrhea, fever, a general feeling of illness (malaise), and weight loss are typical symptoms of tropical sprue. Other symptoms of malabsorption of specific nutrients may also develop. A sore tongue develops from vitamin B₂deficiency. Anemia usually develops as a result of iron, vitamin B₁₂, or folate (folic acid) deficiency, causing fatigue and weakness.

Diagnosis

• • Biopsy
  • Blood tests

A doctor considers the diagnosis of tropical sprue in a person with anemia and symptoms of malabsorption who lives in or has recently visited one of the areas in which the disorder commonly occurs.

A doctor confirms the diagnosis by removing tissue (biopsy) from the small intestine using an endoscope (a flexible viewing tube equipped with a light source and a camera through which a small clipper can be inserted) and examining the tissue under a microscope. The doctor can identify some characteristic changes in the person's small intestine. A stool sample is usually analyzed to exclude parasites or bacteria as a cause.

Blood tests are done to help determine whether people have undernutrition.

Treatment

• • Tetracycline
  • Folate and vitamin B₁₂

Treatment of tropical sprue usually results in a full recovery.

A person suspected of having tropical sprue is treated with an antibiotic. Tetracycline is given for up to 6 months.

Nutritional supplements, especially folate and injections of vitamin B₁₂, are given for several weeks. Other nutritional replacements are given as needed.