Kawasaki Disease or Cat Scratch Disease? A Diagnostic Dilemma: A Paediatric Case Report and Literature Review.

Objective: Kawasaki disease (KD) and atypical cat-scratch disease (CSD) can manifest with fever and similar non-specific symptoms.

Methods: We report the case of an immunocompetent child who presented with signs and symptoms consistent with KD, which overlapped with those of atypical CSD (hepatosplenic form). Subsequently, we conducted a literature review to identify paediatric cases of KD and CSD.

Results: We present the case of a 6-year-old girl with fever, abdominal pain, non-purulent bilateral conjunctivitis, maculopapular rash on the trunk, bilateral cervical lymphadenopathy, and oral mucosa erythema, meeting KD diagnostic criteria. Echocardiography revealed coronary artery dilatations. Despite initial intravenous immunoglobulin (IVIG) treatment eighteen hours later the general condition worsened, with the recurrence of fever, diffuse myalgia, severe abdominal pain, and vomiting. A detailed history revealed a cat scratch three weeks before onset, along with an erythematous nodule on the thumb, axillary lymphadenopathy, a typical hypoechoic splenic lesion in abdominal ultrasonography, and highly elevated IgM and IgG antibodies for Bartonella henselae titres, leading to a diagnosis of atypical CSD. Successful treatment involved a three-month course with erythromycin. Our literature review revealed five cases of co-occurring KD and CSD and six cases where CSD mimicked autoimmune diseases or malignancies.

Conclusion: The presented case illustrated the expanding spectrum of B. henselae infection and emphasised the importance of including it in the differential diagnosis of KD and prolonged fever syndromes. We suggest incorporating abdominal ultrasonography into the initial diagnostic workup, considering it to be essential before empiric therapy initiation.