Makindo Medical Notes

The exact cause of Tropical Sprue remains unclear, but it is believed to be associated with chronic infections or environmental factors common in tropical regions.

About

• A condition characterized by small intestinal malabsorption, primarily seen in tropical and subtropical regions.
• Can develop months to years after an individual leaves an endemic area.
• Endemic in Southeast Asia, the Caribbean, and parts of Central America and India.

Aetiology

• The precise cause is unknown, but it is suspected to involve chronic infection or overgrowth of intestinal flora due to environmental factors.
• Responds to antibiotic therapy, suggesting an infectious component, though no single pathogen has been definitively identified.
• May involve alterations in gut immunity and intestinal permeability.

Clinical Features

• Diarrhoea: Chronic, often leading to dehydration and electrolyte imbalance.
• Weight Loss: Progressive weight loss due to nutrient malabsorption.
• Steatorrhea: Fatty stools, indicative of fat malabsorption.
• Vitamin Deficiencies: Fat-soluble vitamins (A, D, E, K) and B12 deficiencies are common.
• Other Symptoms: Anorexia, fatigue, oedema (due to hypoalbuminaemia), and abdominal distension.
• Symptoms may mimic other malabsorption disorders like coeliac disease or giardiasis.

Investigations

• Blood Tests:
  • Full Blood Count (FBC): May show macrocytic or microcytic anaemia due to iron, folate, or B12 deficiency.
  • Iron Studies: Low serum iron and ferritin levels, indicative of iron deficiency.
  • Folate and B12 Levels: Often low, contributing to macrocytic anaemia.
  • Albumin Levels: May be decreased due to protein malabsorption.
• Stool Studies:
  • Test for fat malabsorption (stool fat quantification).
  • Stool microscopy and cultures to exclude other infections, such as Giardia lamblia.
• Small Bowel Biopsy: Endoscopic biopsy may show villous atrophy, crypt hyperplasia, and inflammatory changes, but less severe than in coeliac disease.
• Lactose Tolerance Test: Often abnormal due to secondary lactose intolerance from mucosal damage.

Management

• Antibiotics:
  • Tetracycline 250 mg four times daily for 3-6 months is the standard treatment.
  • Doxycycline or metronidazole may be alternatives if tetracycline is not tolerated.
• Vitamin and Mineral Supplementation:
  • Folic Acid: 5 mg daily is usually required for several months.
  • Vitamin B12: Administered intramuscularly or orally to correct deficiency.
  • Iron Supplementation: Oral or intravenous iron may be needed to address iron-deficiency anaemia.
  • Additional supplements for fat-soluble vitamins (A, D, E, K) if deficiency is present.
• Dietary Adjustments:
  • High-protein, low-fat diet to aid in recovery and minimize malabsorption symptoms.
  • Address secondary lactose intolerance with lactose-free diet or lactase supplements.
• Follow-up:
  • Monitor weight, nutritional status, and resolution of symptoms.
  • Repeat blood tests to ensure correction of deficiencies and overall improvement.

Prognosis

• With appropriate antibiotic therapy and supplementation, most patients show significant improvement.
• Prolonged untreated cases may result in severe malnutrition and complications from vitamin deficiencies.
• Recurrence is possible, especially if the patient returns to an endemic area.

References

• Tropical Sprue Overview and Management - Gastroenterology Journal
• Tropical Sprue and Small Intestinal Diseases - Clinical Perspectives