An 8-year-old male presented with fever, pain abdomen and vomiting for 6 days. He had tachycardia, tachypnea, left cervical lymphadenopathy, hepato-splenomegaly and an eschar hidden behind left ear (Fig. 1). Laboratory work-up was non-contributory except thrombocytopenia and elevated hepatic transaminases. Child was started on oral doxycycline. IgM-ELISA for scrub typhus was subsequently reported positive. He became afebrile within 36 hours, and was discharged after 7 days following normalization of clinico-laboratory parameters.

Fig.1 Eschar behind left ear.

Eschar is a pathognomonic sign of scrub typhus and if sought carefully, seen in up to two-third (7% - 68%) of pediatric cases. It begins as a small-papule at the site of mite-bite, enlarges, undergoes central-necrosis and acquires a black crust with surrounding erythema, resembling a cigarette burn. Under appropriate epidemiological setting, painless eschar in a child with fever and multi-system involvement suggests scrub typhus. Other conditions associated with eschar formation are spider-bite (painful), tularaemia (usually on fingers), post-trauma, anthrax (pre-existing skin breach), some other rickettsiosis, and disseminated mycosis.