A research team from Jeonbuk National University (JBNU) College of Medicine and Jeonbuk National University Hospital announced a study that reexamines the eschar, the characteristic skin lesion of scrub typhus, not merely as a diagnostic marker but as a key biological space where pathogen entry and proliferation, immune responses, and systemic dissemination begin.

The study involved Professor Chang-Seop Lee (corresponding author) of the Division of Infectious Diseases, JBNU College of Medicine; Professor Jin Park of Dermatology; and Professor Jin-Gyeong Choi of the Department of Immunology. It was conducted jointly with researchers from Seoul National University College of Medicine and the Korea Research Institute of Standards and Science. The paper was published in Clinical Microbiology Reviews on September 4, 2026.

Clinical Microbiology Reviews is a leading review journal in clinical microbiology and infectious diseases published by the American Society for Microbiology (ASM). It is a top-tier international journal with a current impact factor of 20.7.

Based on previous studies, the researchers comprehensively presented an infection process in which Orientia tsutsugamushi, having entered the skin via chigger mites, interacts with immune cells at the eschar site and proliferates, then disseminates systemically via the lymphatic system and bloodstream. In particular, they proposed the eschar as **the 'starting point of infection' where the pathogen and the host immune system first engage in earnest**.

They also noted that because pathogens are present at high concentrations in the eschar during early disease, molecular diagnosis using an eschar swab may be advantageous for early pathogen detection compared with blood-based tests. They suggested the potential for future development into next-generation rapid diagnostic technologies such as CRISPR, digital PCR, and biosensors.

Corresponding author Professor Chang-Seop Lee is a leading domestic researcher on scrub typhus who has focused on the disease for more than 20 years and published some 40 related papers. Professor Lee stated, 'The eschar is not a mere skin lesion but the starting point of infection where the pathogen and the human immune system first meet,' and added, 'We hope this study will contribute to understanding the pathophysiology of scrub typhus and provide a basis for developing rapid early-detection technologies using the eschar.'

Article Title: Eschar in scrub typhus: clinical signature, immunopathogenesis, and diagnostic implications

Journal: Clinical Microbiology Reviews

Publication Date: September 4, 2026

Article: e0034825

DOI: 10.1128/cmr.00348-25