Cat Scratch Disease: An Unusual Case of Right Inguinal Lymphadenitis Due to Bartonella henselae

Cat scratch disease (CSD) is caused by a bacterial infection due to Bartonella henselae and is associated with young cats and kittens. CSD commonly occurs as regional lymphadenitis in the setting of subacute regional lymphadenopathy predominantly in children and young adults. The prognosis for immunocompetent patients is favorable with complete recovery, however, immunocompromised adults can progress to life-threatening complications such as neuroretinitis, osteomyelitis, and bacillary angiomatosis. B. henselae is transmitted from cats to humans through scratching or biting when located on the cat's claws or oral cavity. In 1% of diagnosed cases, patients developed this disease without ever receiving an animal scratch.  We present a case of a 29-year-old immunocompetent male developing severe right inguinal pain with concern for an incarcerated inguinal hernia. He reported exposure to a vaccinated six-month-old kitten but denied any recent scratches or bites. His infectious workup revealed right inguinal lymphadenitis on CT imaging and subsequent lymph node biopsy confirmed a diagnosis of CSD. He was treated with a short course of oral doxycycline for CSD and opioids for pain management. This case illustrates the importance of thorough complete history and physical taking even in immunocompetent patients and early recognition with prompt targeted treatment of Bartonella lymphadenitis to prevent unfavorable outcomes.