Eschar and neck lymphadenopathy caused by Francisella tularensis after a tick bite: a case report

INTRODUCTION: In 25 to 35% of cases, the aetiological agent of scalp eschar and neck lymphadenopathy after a tick bite remains undetermined. To date, Rickettsia slovaca, Rickettsia raoultii and more recently Bartonella henselae have been associated with this syndrome. CASE PRESENTATION: A four-year-old Caucasian boy was admitted to hospital with fever, vomiting and abdominal pain. On physical examination, an inflammatory and suppurating eschar was seen on the scalp, with multiple enlarged cervical lymph nodes on both sides. Although no tick was found in this scalp lesion, a diagnosis of tick-borne lymphadenopathy was suggested, and explored by serology testing and polymerase chain reaction of a biopsy from the eschar. Francisella tularensis DNA was found in the skin biopsy and the serology showed titres consistent with tularaemia. CONCLUSION: This is, to the best of our knowledge, the first reported case of scalp eschar and neck lymphadenopathy after tick bite infection caused by F. tularensis.