Cat scratch disease--heterogeneous in clinical presentation: five unusual cases of an infection caused by Bartonella henselae.

BACKGROUND: Cat-scratch disease (CSD) is common in children, however the wide spectrum of the clinical presentation of CSD may lead to delayed diagnosis. An atypical presentation of CSD includes in its differential diagnosis diseases such as tuberculosis, other mycobacterioses, Epstein-Barr-Virus infection (EBV) or malignant disease. Since, in a small number of cases, these diseases may be present concurrently with an active CSD, it is important to consider CSD early in the differential diagnosis and order the appropriate tests. These tests include serology and, where possible, histology including molecular diagnostic methods on tissue specimens. PATIENTS AND METHOD: We performed a case series of five patients treated in our hospital with a clinical diagnosis of cat-scratch disease, confirmed by serology. An analysis of the history and clinical symptoms associated specifically with an atypical presentation of CSD was performed. RESULTS: The clinical presentation of CSD no longer encompasses the original typical description from 1950, but rather presents with a wide spectrum of signs and symptoms, including the absence of a documented cat scratch, fever, primary lesions or peripheral lymphadenopathy. Low density lesions in spleen, liver and lymph nodes are typical findings in ultrasound, MRI, or CT. Ignoring CSD as a possibility in investigating possible malignancy or tuberculosis could lead to unnecessary hospitalisation and delay in the proper treatment. CONCLUSION: CSD should also be considered in differential diagnosis of any patient with intraabdominal lymphadenopathy, abdominal pain and fever of unknown origin. A careful history is important, however, often patients with CSD have no history of contact with cats. Therefore in atypical cases of CSD the finding of other clinical symptoms and performance of specific diagnostic tests is important. Our experience suggests that early serological testing for Bartonella henselae should be performed and may avoid invasive diagnostic procedures.