Pediatric Bartonella Infection (Cat Scratch Disease) Presenting as Inguinal Lymphadenopathy

Abstract

Cat scratch disease is an infectious disease resulting from inoculation of Bartonella species through a cat scratch or bite, often presenting as an erythematous papule at the site of inoculation with nearby painful lymphadenopathy. The diagnosis of this disease is complicated by a wide variety of clinical presentations, as the primary lesion may not be initially noticed. Furthermore, cervical and axillary lymph nodes are the most commonly involved regions of tender lymphadenopathy, but there have been reported cases that do not fit the typical clinical picture – such the case discussed in this report of a pediatric Bartonella henselae infection that initially presented as left inguinal lymphadenopathy with underlying necrosis and abscess formation. In this case, a 9-year-old boy presented to the ED with a 4-day history of increasing mass in the left groin, as well as a subjective fever for the previous 2 days. An ultrasound revealed a necrotic abscess in the left inguinal lymph node which necessitated empiric antibiotic therapy and surgical excision; titers revealed a recent infection with Bartonella henselae. Atypical presentations of cat scratch disease, such as inguinal lymphadenopathy, have historically confounded the diagnosis. However, positive serology studies ultimately yielded the correct diagnoses in these children. Given that cat scratch disease can present in an atypical fashion in approximately 5 - 25% of cases, physicians should keep the disease on the differential even when presented with rare presentations such as inguinal lymphadenopathy; serological testing for B. henselae can be utilized once more likely etiologies have been ruled out.