Atypical Cat Scratch Disease With Splenic Lesion Mimicking Kawasaki Disease in a Healthy 5-Year-old Girl

Background: Atypical cat scratch disease (CSD) and Kawasaki disease (KD) are differential diagnoses of pediatric febrile illnesses. Diagnosing atypical CSD can be challenging because of its wide range of symptoms. However, its similarity to KD has rarely been addressed.Methods: We present the case of a 5-year-old girl with atypical CSD and splenic lesions who fulfilled the diagnostic criteria for KD. We also conducted a literature review of previous cases in which CSD was suspected alongside KD and detailed the diagnosis and treatment processes.Results: A previously healthy 5-year-old girl with prolonged fever and symptoms resembling those of KD was admitted to our hospital. There was no evidence of an abnormal coronary artery, and her condition did not improve after the initial treatment for KD and bacterial infection. A history of contact with cats and multiple granulomatous lesions in the spleen on abdominal ultrasonography led to a clinical diagnosis of atypical CSD. Trimethoprim-sulfamethoxazole treatment resulted in symptom resolution. Elevated serum Bartonella henselae IgG and IgM antibodies confirmed the diagnosis of CSD. In this case, we avoided second-line treatment for KD with an alternative CSD diagnosis. Additionally, we identified 4 documented cases of CSD presenting with KD-like features in the literature. Intravenous immunoglobulin was ineffective in all cases, including the present case.Conclusions: In cases of atypical CSD where KD is suspected, actively seeking organ-specific symptoms may facilitate an early clinical diagnosis of CSD. Adopting this approach could yield multiple advantages, including reduced invasiveness for the patient and decreased healthcare-related expenditures.