Bartonellosis (also called Carrión's Disease, Oroya Fever or Peruvian Wart) is caused by the bite of mosquitoes of the Lutzomyia genus belonging to the Psychoid family. They are nocturnal blood-sucking insects, with complete metamorphosis. About 450 species are known, distributed throughout the American continent, mostly in tropical and subtropical areas. In Ecuador, sporadic cases have been reported, with certain characteristics such as, for example, not presenting the blood phase and, in the eruptive phase, not being aggressive. Here, we present a unique case of a 13-year-old boy with a history of congenital heart disease, who presented a clinical picture of one year of evolution suggestive of dermatosis, characterized by papules and nodules that occasionally bleed. The mother reports living in an area of lush vegetation and being in contact with bites. The results of blood count, peripheral blood smear, liver function and coagulation: normal. Blood sample: Negative Bartonella spp. PCR biopsy ribC gene: Positive B. bacilliformis. This case demonstrates the importance of maintaining an entomo-epidemiological surveillance system in patients exposed to arthropod bites that allows for timely detection of cases in order to make a diagnosis and provide timely treatment.