title: Eschar in scrub typhus: a valuable clue to the diagnosis.
abstract: BACKGROUND
  Scrub typhus is an acute febrile illness widely prevalent in the 'tsutsugamushi triangle' region of the world. Clinical features include fever, myalgia, headache, rash, and a pathognomonic eschar. An eschar is formed by the bite of chigger mite that inoculates the causative agent of Scrub typhus Orientia tsutsugamushi. The aim of this study is to determine the most common sites of eschars over the bodies of patients with Scrub typhus.
  
  
  METHODS
  In a retrospective analysis, we examined a total of 418 patients who presented to Christian Medical College, Vellore between 2009 and 2012 with an acute febrile illness and an eschar on clinical examination and confirmed to have scrub typhus with a positive Scrub typhus IgM ELISA test. We studied the distribution of eschars over the bodies of 418 patients with Scrub typhus.
  
  
  RESULTS
  There was a significant difference in the distribution of eschars between males and females with a preponderance of the chest and abdomen (42.3%) among females and the axilla, groin and genitalia (55.8%) in males. Some unusual sites of an eschar were the cheek, ear lobe and dorsum of the feet.
  
  
  CONCLUSIONS
  The eschar is the most useful diagnostic clue in patients with acute febrile illness in areas endemic for Scrub typhus and therefore should be thoroughly examined for its presence especially over the covered areas such as the groin, genitalia, infra-mammary area and axilla.
authors.affiliation: Department of Medicine, Christian Medical College, Vellore, Tamil Nadu, India.
authors.forename: A P
authors.initials: AP
authors.lastname: Kundavaram
authors.forename: A J
authors.initials: AJ
authors.lastname: Jonathan
authors.forename: S D
authors.initials: SD
authors.lastname: Nathaniel
authors.forename: G M
authors.initials: GM
authors.lastname: Varghese
mesh_terms: D000005:Abdomen; D000328:Adult; D000818:Animals; D001096:Arachnid Vectors; D001365:Axilla; D001733:Bites and Stings / Q000473:pathology*; D002610:Cheek; D004431:Ear, External; D005260:Female; D005528:Foot; D005837:Genitalia, Male; D006119:Groin; D006801:Humans; D008297:Male; D008875:Middle Aged; D008925:Mites; D012285:Orientia tsutsugamushi; D012189:Retrospective Studies; D012612:Scrub Typhus / Q000175:diagnosis* / Q000473:pathology; D012737:Sex Factors; D013909:Thorax