Synopsis
Recognise Whipple disease and travel-related malabsorption without collapsing them into a single tropical diagnosis, select tissue, molecular and stool tests with microbiology, and begin prolonged organism-specific therapy only with infection and gastroenterology expertise using current reference-laboratory, UKHSA, BNF and local imported-infection guidance.
- Classic Whipple disease is caused by Tropheryma whipplei and often presents with years of migratory seronegative arthralgia before weight loss, diarrhoea, abdominal pain, nodes or systemic disease.
- Neurological, ocular and culture-negative endocarditis presentations can occur without obvious diarrhoea; cognitive change, supranuclear gaze disorder or oculomasticatory movements are high-risk clues.
- Duodenal histology with PAS-positive macrophages plus organism-specific PCR on appropriately chosen samples supports diagnosis; stool or saliva PCR alone can reflect carriage.
- Exclude Whipple disease before escalating immunosuppression in a credible multisystem inflammatory mimic because corticosteroids or biologics can accelerate infection.
- Tropical malabsorption is a syndrome, not an aetiology: travel geography, duration, food and water, freshwater, barefoot soil, medicines, immune state and onset guide testing.
- Giardia, Strongyloides, HIV-related infection, intestinal tuberculosis, coeliac disease and pancreatic disease are generally more defensible targets than assuming tropical sprue.
- UK SMI guidance supports Giardia and Cryptosporidium in primary testing for symptomatic diarrhoea, with travel- and immune-specific parasite investigations added explicitly.
- Treat severe dehydration, electrolyte depletion, malnutrition and refeeding risk immediately while diagnostic sampling continues.
Key red flags
Cognitive or behavioural change, ataxia, hypothalamic features, supranuclear gaze palsy, myoclonus or oculomasticatory movements requires urgent CNS-aware diagnostic and treatment planning.
Valvular infection, embolic phenomena or heart failure with negative routine cultures can be T. whipplei even without gut symptoms; valve tissue PCR may be decisive.
Dehydration, oedema, profound anaemia, tetany, arrhythmia or neurological deficiency requires admission and cautious nutrition support while cause-specific tests proceed.
Investigation priorities
Obtain multiple proximal and distal duodenal biopsies for PAS staining and pathology when classic Whipple or another enteropathy is suspected.
Management branches
Arthralgia plus malabsorption, neurological disease or culture-negative endocarditis makes T. whipplei plausible.
- Stop diagnostic anchoring, review prior immunosuppression and involve gastroenterology, infection or microbiology and the organ-specific team.
- Obtain duodenal histology and reference PCR from the most informative compartments before antibiotics when safe, without delaying treatment for unstable CNS or cardiac disease.
- Confirm concordance and exclude PAS or PCR mimics before committing to prolonged therapy.
- Plan a CNS-penetrating induction and prolonged eradication regimen with relapse surveillance through specialists.