Cat Scratch Disease

M.B. is a 48-year-old female with a history of multiple prior hospitalizations for sepsis/bacteremia, cellulitis, and peritonitis, presenting with a new right lower extremity shin wound present for ~6 weeks. She is accompanied by her sister, an experienced medical assistant and reliable historian, who provides most of the history. They describe a ~2-inch (5.1 cm) right shin laceration with a ~0.5-inch (1.3 cm) opening, surrounded by erythema, swelling, warmth, and pain, with serosanguinous drainage for several weeks to months. She has completed amoxicillin for 2 weeks followed by clindamycin for 2 weeks without improvement. She denies systemic symptoms (fever, chills, chest pain, shortness of breath, abdominal pain) and does not appear acutely ill. At baseline for over 10 years, she is slow to respond, requires significant assistance, cannot live independently, and is not a reliable historian, though she is cooperative and fully mobile.