๐ด Tropical Sprue is a malabsorption syndrome endemic to tropical regions.
Its cause remains unclear but is thought to involve chronic infection + environmental factors.
๐ก Key clue: It may develop even months or years after leaving an endemic area.
๐ About
- Malabsorptive disorder of the small intestine found in tropical/subtropical regions (SE Asia, Caribbean, Central America, India).
- Distinguished from coeliac disease: no gluten sensitivity, but similar villous atrophy.
- Responds dramatically to antibiotics + folate, suggesting an infectious trigger.
๐งฌ Aetiology
- Exact cause unknown โ likely chronic infection or bacterial overgrowth due to poor sanitation + high enteric pathogen load.
- Environmental and immune factors โ impaired mucosal absorption.
- Strong response to tetracyclines supports an infective role, but no single pathogen proven.
๐ฉบ Clinical Features
- ๐ฉ Chronic diarrhoea โ watery, sometimes steatorrhoeic.
- โ๏ธ Weight loss & failure to thrive in prolonged cases.
- ๐ณ Steatorrhoea from fat malabsorption.
- ๐ฉธ Vitamin deficiencies: Folate & B12 (macrocytic anaemia), fat-soluble vitamins A/D/E/K.
- ๐ค Other: Fatigue, oedema (hypoalbuminaemia), abdominal distension.
- May mimic: coeliac disease, giardiasis, or tropical infections.
๐งช Investigations
- ๐ Bloods:
- FBC: Macrocytosis (folate/B12 deficiency), or microcytosis (iron deficiency).
- โ Albumin โ protein malabsorption.
- ๐ฉ Stool studies: Fat quantification โ confirms steatorrhoea; rule out Giardia.
- ๐ฌ Small bowel biopsy: Villous atrophy + crypt hyperplasia (less severe than coeliac).
- ๐ฅ Lactose tolerance test: Often abnormal โ secondary lactose intolerance.
๐ Differential Diagnosis
- Coeliac disease (anti-tTG, EMA antibodies).
- Giardiasis (stool microscopy, antigen testing).
- Whippleโs disease.
- Chronic pancreatitis (enzyme deficiency rather than mucosal disease).
๐ Management
- ๐ Antibiotics:
- Tetracycline 250 mg QDS for 3โ6 months (standard).
- Doxycycline or Metronidazole โ alternatives if tetracycline not tolerated.
- ๐ Folate 5 mg/day โ rapid haematological & symptomatic improvement.
- ๐ Vitamin B12: IM/oral replacement if low.
- ๐ฉธ Iron supplementation for deficiency anaemia.
- ๐ Diet: High-protein, low-fat, lactose-restricted if intolerance present.
- ๐ Monitoring: Weight, bloods, and resolution of diarrhoea/nutritional deficits.
๐ฎ Prognosis
- Excellent with appropriate antibiotics + supplementation.
- Relapse possible, especially on return to endemic regions.
- Untreated โ severe malnutrition, vitamin deficiency complications, growth failure.
๐ References
๐ Teaching Pearl:
If you see a patient from or recently returned from the tropics with chronic diarrhoea, weight loss, and megaloblastic anaemia โ think Tropical Sprue.
Dramatic improvement with tetracycline + folate is both diagnostic & therapeutic.