Scrub Typhus with Acute Respiratory Distress Syndrome: A Case Report with Narrative Review of Current Management Guidelines

Abstract

Scrub typhus, also known as tsutsugamushi disease, is an acute rickettsial zoonotic infectious disease caused by mite-borne bacterium Orientia tsutsugamushi. The disease spectrum can range from mild, nonspecific, self-limiting febrile illness to rapidly progressive, potentially lethal multiorgan dysfunction involving the lungs, heart, kidneys, liver and brain. Acute respiratory distress syndrome (ARDS) is a serious complication of scrub typhus.

A 51-year-old male patient from Amini Island, Lakshadweep, was admitted to our hospital with a history of five days of fever, headache, bilateral inguinal lymphadenopathy and acute onset of breathing difficulty for one day. A physical examination revealed the presence of an eschar on the right thigh. A serological and imaging diagnostic evaluation identified scrub typhus with thrombocytopenia, which subsequently progressed to ARDS, despite early initiation of oral doxycycline and adjunctive steroids. At FiO₂ of 35% with a PaO₂ of 75 mmHg and SpO₂ of <90%, PaO₂/FiO₂ and SpO₂/FiO₂ ratios were 214 and <257, respectively, suggestive of mild ARDS. He recovered completely after 2 weeks of appropriate treatment and supportive care.

Scrub typhus is a critical differential diagnosis for acute undifferentiated fever with thrombocytopenia or haemorrhage, even in areas not strictly endemic. Patients with clinically suspected scrub typhus should be instituted empirical antibiotic treatment promptly—even before laboratory confirmation, to prevent progression to ARDS. Compared to the 2012 Berlin definition, the 2024 revised diagnostic criteria for ARDS - "New Global Definition" - improve early detection, enhance inclusivity for non-intubated patients, and allow for diagnosis in resource-limited settings.