A Case Report of Severe Scrub Typhus with Unexplained Multiple Organ Dysfunction and Literature Review

Objective: To explore the difficulties in the early diagnosis, clinical features and treatment strategies of severe scrub typhus, and to enhance clinicians' understanding of multiple organ dysfunction (MODS) caused by it. Methods: A retrospective analysis was conducted on the data of one case that presented with high fever, shock, acute respiratory distress syndrome (ARDS), acute kidney injury (AKI), abnormal liver function and was eventually diagnosed with severe scrub typhus, and the relevant literature was reviewed. Results: The patient was an elderly male who was admitted to the Department of Respiratory Medicine due to "fever and cough for 5 days". Upon admission, the patient was in critical condition and rapidly progressed to septic shock, ARDS (requiring invasive mechanical ventilation), AKI, liver injury, and coagulation dysfunction, and was transferred to the ICU 2 days after admission. Early empirical broad-spectrum antibacterial treatment was ineffective, and a black eschar was found in the right thoracolumbar area during a detailed re-examination. The patient denied travel history, fieldwork, outdoor activities, etc. As the patient lived alone and his family members were unable to provide more medical history, there was a high suspicion of scrub typhus based on the characteristic black eschae on the skin at the time. Metagenomic sequencing of bronchoalveolar lavage fluid (BALF mNGS) suggested that scrub typhus was in the middle of the body, and the antibiotic was changed to doxycycline before reporting. After 48 hours, the patient's body temperature began to drop, hemodynamics gradually stabilized, organ function gradually recovered, and he was discharged after 14 days. Conclusion: Severe scrub typhus can lead to MODS and progress to life-threatening MOF, and eschar is a key clue for early diagnosis. For patients with severe infections of unknown cause, a very detailed and comprehensive skin examination should be performed, regardless of whether there is a clear epidemiological history or not. Early application of treatments such as doxycycline is key to improving prognosis.