Skin ulcer and maculopapular rash with inguinal lymph node enlargement: a case report of a 46-year-old female patient from north-eastern Poland with <i>Rickettsia</i> spp. and <i>Francisella tularensis</i> co-infection

North-eastern Poland is an endemic region for tick-borne diseases, especially Lyme disease and tick-borne encephalitis. However, less common diseases such as rickettsiosis and tularemia may occur after a tick bite. In this paper we present a rare case of Rickettsia spp. and Francisella tularensis co-infection in a 46-year-old female patient with no history of travel and no chronic diseases, confirmed by serological and molecular tests. The symptoms appeared 5-7 days after the tick bite and lasted for 2 weeks. On physical examination, a maculopapular rash over the entire body, an ulcer on the left lower extremity, and an enlarged inguinal lymph node were noted. We concluded that rare diseases such as rickettsiosis and tularemia should be included in differential diagnosis of fever, lymphadenopathy and skin changes after a tick bite. Co-infection with Rickettsia spp. and F. tularensis is possible in patients after a tick bite. Quick diagnosis allows proper treatment (with doxycycline) and complete recovery.