A 60-year-old man presented with a seven-day history of fever, headache, fatigue, and decreased urine output. On examination, he was febrile (38°C), and had tachycardia. A blackish skin lesion was noted on the right side of his neck (Fig. 1). Eschar was not preceded by any pain or itching. His hemogram revealed a hemoglobin count of 11.8gm/dL, total leukocyte count of 6300/mm3, and a platelet count of 80,000/mm3. His liver functions were normal except for transaminase elevation (SGPT: 112U/mL, SGOT: 120U/mL). His kidney function tests and urine analysis were normal. Blood and urine cultures showed no growth. Weil Felix reaction was positive for OX-K in a titer of 1:160. DNA polymerase chain reaction (PCR) for Orientia tsutsugamushi was positive in a blood sample. A diagnosis of scrub typhus was established. The patient was managed with doxycycline and supportive measures. The patient improved within the following five days.

Fig. 1.

Blackish skin lesion on the right side of the patient's neck.

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Scrub typhus, a mite-borne infection caused by Orientia tsutsugamushi, is very common in the Asia-Pacific region.1,2 The disease is so called because of the type of vegetation where the mite is present. The mite bites are painless and the lesion begins as a red induration, that eventually vesiculates and ruptures to form an eschar.2 The patients may present with fever, headache, myalgia, and hearing loss, which can be complicated by encephalitis, hepatitis, and pulmonary and cardiac involvement.2,3 Scrub typhus is often diagnosed clinically based on the characteristic symptoms and presence of eschar, which appears on lower extremities and axillary or genital regions and may occur in around 60% of cases.4 The eschar at the bite site is the single most useful diagnostic clue and thus febrile patients without any localizing signs should be thoroughly examined for its presence. Early diagnosis and treatment with doxycycline can be life saving.