Which clinical history findings are characteristic of scrub typhus?

Updated: Apr 19, 2018
  • Author: David J Cennimo, MD, FAAP, FACP, FIDSA, AAHIVS; Chief Editor: Russell W Steele, MD  more...
  • Print

Patients with scrub typhus may present early or later in the course of their disease. In the United States, a history of travel to the endemic area must be sought, specifically probing for exposures in rural areas and contact with vegetation or the ground. [3, 6, 13]

Inoculation through the chigger bite is often painless and unnoticed. The incubation period lasts 6-20 days (average, 10 days). After incubation, persons may experience headaches, shaking chills, lymphadenopathy, conjunctival infection, fever, anorexia, and general apathy. The fever usually reaches 40-40.5°C (104-105°F).

A small painless papule initially appears at the site of infection and enlarges gradually. An area of central necrosis develops and is followed by eschar formation. The eschar (if present) is well developed at the initiation of the fevers, which may drive the patient to seek medical attention. [3, 4, 11, 34, 35]

Diagnosing scrub typhus early in its course can be difficult because many conditions can present with a high fever; however, the presentation of the rash, a history of exposure to endemic areas, and the presentation of the sore caused by the bite can be diagnostic.

Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!