Beyond Cat Scratch Disease: A Case Report of Bartonella Infection Mimicking Vasculitic Disorder

Cat scratch disease (CSD) is a bacterial disease caused by Bartonella henselae and it is mainly characterized by self-limiting lymphadenopathy in the draining site of a cat scratch or bite. We report a patient with history of fever, swelling lymph nodes, vasculitic-like skin lesions, and positivity of Bartonella serology initially considered as expression of a disimmune disease. 1. Introduction Cat scratch disease (CSD) is a bacterial disease caused by Bartonella henselae. It is mainly characterized by self-limiting lymphadenopathy (especially around the head, neck, and upper limbs) in the draining site of a cat scratch or bite. Other general symptoms include fever (usually less than 38°C), fatigue, loss of appetite, headache, rash, sore throat, and an overall ill feeling. In such cases, someone might have infections of the liver, spleen, heart, lungs, joints, bones, or a lingering high fever without other symptoms. Some get an eye infection (Parinaud oculoglandular syndrome), with symptoms including redness of the eye and swollen lymph nodes in front of the ear. Others may develop inflammation of the brain, although this is rare. All of these complications usually resolve without any lasting illness and the majority of mild-to-moderate cases of CSD resolve in 1 to 2 months without any antimicrobial therapy. The therapeutic approach varies on the basis of the clinical manifestations and immune status of the patient. There is a paucity of data in the literature as to the most effective therapy, with most data presented as part of case series rather than randomized controlled trials. There is a significant divide in the literature between in vitro efficacy of antibiotics and the ability to successfully treat in clinical practice. In vitro, Bartonella species have been found to be susceptible to a number of antimicrobial agents including macrolides, aminoglycosides, β-lactams, expanded-spectrum cephalosporins, trimethoprim-sulfamethoxazole, rifampin, and ciprofloxacin. Since the causative bacteria cannot be easily cultured from human lymph node samples, the diagnosis usually relies on epidemiological, clinical, histological, and serological criteria [1]. According to Bergmans et al. [2], a diagnosis of CSD usually requires three of the following four criteria: (I) a history of contact with a cat and the presence of a scratch or primary lesion of the skin, eye, or mucous membrane; (II) a positive cat scratch skin test reaction; (III) negative laboratory testing for other causes of lymphadenopathy; (IV) characteristic histopathological findings in a lymph