Neurological Facets of Scrub Typhus: A Comprehensive Narrative Review

Abstract

Scrub typhus is one of the most frequent causes of acute febrile illness in South and South-east Asian countries. Neurological features accompany 20% of scrub typhus infections, and may affect the central or peripheral nervous system, and sometime, may even occur in combination. Of late, its recognition among clinicians has increased with widening detection of its cutaneous hallmark, called eschar. Multiple mechanisms underlie neurological involvement, including direct invasion (meningitis, encephalitis), vasculitis (myositis) or immune-mediated mechanisms (opsoclonus, myoclonus, optic neuritis, Guillain-Barre syndrome). Despite an immunological basis for several neurological manifestations, response to doxycycline is remarkable, although immune therapy may be necessary for severe involvement. Scientific literature on scrub typhus neurology chiefly emanates from case reports, case series and small studies, and a comprehensive review is warranted to aid clinicians in recognising neurological involvement. This review aims at enriching this gap, and summarises clinical features, laboratory findings, and treatment options for various neurological facets of scrub typhus.

Keywords: Neurology; opsoclonus; orientia tsutsugamushi; scrub typhus; vasculitis.

Figure 1

Sites of distribution of eschar of scrub typhus on the human body

Figure 2

Pathogenesis of neurological features of scrub typhus

Figure 3

Timelines of evolution of neurological manifestations in scrub typhus