Kaposi's Sarcoma and Bartonella Coinfection in HIV-Positive Patient

Introduction: Kaposi's sarcoma is a multifocal malignant neoplasm of endothelial cells, its etiological agent is HHV-8 and it constitutes one of the defining pathologies of AIDS. It represents approximately 12% of cancers diagnosed in people living with HIV. Bacillary angiomatosis (AB) is a rare infectious disease caused by bacteria of the genus Bartonella spp., transmitted by vectors such as fleas, lice, and mosquitoes. In patients with human immunodeficiency virus (HIV) infection with a CD4+ T-cell count <100 cells/µL, it is associated with angiomatous lesions with neovascularization that involve the skin and, to a lesser extent, mucous membranes, liver, spleen, and bones. Clinical case: the case of a 48-year-old male patient with a history of HIV on HAART for 15 years, who was admitted for an outpatient infectious disease clinic due to violaceous nodular lesions in the right and left MMII, upper eyelid. left and oropharynx. During hospitalization, a blood culture report was obtained that was positive for Bartonella and a biopsy result of a lower limb lesion concluded that Kaposi's Sarcoma was present. Upper gastrointestinal endoscopy and chest and abdominal tomography were performed, which showed the visceral and systemic involvement of Kaposi's Sarcoma. The HIV genotype is performed, resulting in resistance to antiretrovirals, so the medication is changed and chemotherapy is started, with the patient showing a good response and improvement. Conclusion: HIV-related Kaposi's Sarcoma affects AIDS patients in a much more severe, aggressive, and fulminant manner compared to other immunodeficient groups. However, when presenting characteristic lesions, we must consider its main differential diagnosis: Bacillary Angiomatosis, which, even very uncommonly, may occur simultaneously.