Eschar is not the sole clue for scrub typhus: a retrospective analysis of pediatric scrub typhus without eschars.

Abstract

Objective: This study aims to investigate the clinical characteristics and analyze the diagnostic approaches employed for pediatric cases of scrub typhus (ST) that present without eschars.

Methods: A retrospective analysis was conducted on 256 ST cases hospitalized at Kunming Children's Hospital in Yunnan Province, China, from January 2015 to November 2022. Patients were categorized into an eschar group (n = 213) and a non-eschar group (n = 43). Clinical data were collected and analyzed for significant differences between the groups. This study particularly highlights the diagnostic methods for confirming ST in cases without eschars.

Results: The non-eschar group exhibited a higher incidence of pneumonia, a lower history of outdoor activities prior to onset, and a longer hospital stay; however, the remaining clinical and laboratory characteristics did not show statistically significant differences. The most common site for eschar formation was the axilla (12.7%, n = 27), followed by the groin (9.4%, n = 20) and auricle (8.9%, n = 19). Other notable sites included the scalp (7.5%, n = 16) and shoulder (6.6%, n = 14). The Weil-Felix test (OXK) demonstrated a positivity rate of 69.7% (23 out of 33 cases), cerebrospinal fluid (CSF) PCR had a positivity rate of 50.0% (3 out of 6 cases), and blood PCR exhibited a positivity rate of 92.3% (24 out of 26 cases).

Conclusion: These findings underscore the importance for clinicians to consider ST in pediatric patients, even in the absence of eschars. A comprehensive evaluation based on epidemiology, symptoms, signs, and laboratory characteristics is essential. Blood PCR testing methods are recommended.

Clinical trial number: Not applicable.