Can scrub typhus present with diarrhea?

Can Scrub Typhus Present with Diarrhea?

Yes, scrub typhus can definitely present with diarrhea, occurring in approximately 18-45% of cases, making it a recognized gastrointestinal manifestation of this rickettsial infection.

Clinical Presentation of Gastrointestinal Symptoms

Scrub typhus commonly presents with various gastrointestinal manifestations beyond the classic fever and eschar. The spectrum includes:

• Diarrhea: Present in 18% of cases in one study 1 and up to 45% in another cohort 2
• Vomiting: Occurs in 31-65% of patients 1, 2
• Nausea: Seen in approximately 60% of cases 2
• Abdominal pain: Present in 16-20% of patients 1, 2
• Hematemesis or melena: Occurs in 25% of severe cases 2

Underlying Pathophysiology

The gastrointestinal symptoms in scrub typhus result from Orientia tsutsugamushi-induced vasculitis and perivasculitis affecting multiple organ systems 2, 3. This vasculitic process leads to:

• Hepatomegaly (40-67% of cases)
• Elevated liver enzymes (70-80% show transaminitis)
• Gastritis and gastric erosions on endoscopy
• Duodenal ulcers in some cases

The key differentiating endoscopic finding is that stomach lesions are more frequent and severe than duodenal lesions 2.

Clinical Context and Severity

When diarrhea occurs as part of scrub typhus, it typically appears alongside:

• Universal fever (100%)
• Headache (33%)
• Cough (32-38%)
• Altered sensorium in severe cases (23%)

Importantly, the presence of gastrointestinal symptoms including diarrhea does not necessarily indicate milder disease—in fact, patients with multiple organ involvement (including GI dysfunction) have significantly higher morbidity and mortality 1.

Diagnostic Pitfalls

The nonspecific nature of diarrhea in scrub typhus creates diagnostic challenges:

• Scrub typhus may be mistaken for enteric fever, which also presents with fever and diarrhea/constipation 4
• The classic eschar is only present in 23-40% of cases 1, 2, so its absence should not exclude the diagnosis
• In endemic areas (rural South Asia, Southeast Asia, Western Pacific), maintain high clinical suspicion in febrile patients with diarrhea and hepatosplenomegaly 4

Practical Approach

When evaluating a febrile patient with diarrhea from endemic regions:

1. Look specifically for an eschar in hidden areas (back, genitalia, abdomen, axillae)
2. Check for hepatosplenomegaly and conjunctival congestion on examination
3. Order liver function tests—transaminitis with hyperbilirubinemia strongly suggests scrub typhus over simple gastroenteritis
4. Request IgM serology (IFA is the reference standard) 1
5. Consider empiric doxycycline if clinical suspicion is high, as delayed treatment increases mortality risk (up to 4-32% in severe cases) 4, 1

The combination of fever, diarrhea, hepatosplenomegaly, and transaminitis in a patient from an endemic area should prompt immediate consideration of scrub typhus, even without an identifiable eschar.