RESUMO
Cat-scratch disease is a well-known infection in childhood. It usually presents as tender lymphadenopathy and should be included in the differential diagnosis of any lymphadenopathy syndrome. An history of exposure to cats supports the suspect and a positive serologic test to Bartonella henselae confirms the diagnosis. Ultrasound is the first line radiologic imaging performed in case of lymphadenopathy. The presence of hypoechoic lobular or oval mass with central hyperaemia and a possible adjacent fluid collection and surrounding oedema may differentiate the disease from other aetiologies. We describe the case of a 7-year-old girl presenting with an axillary lymphadenopathy, without a reported recent history of exposure to cats, with sonographic findings suggestive for cat-scratch disease. In this case, ultrasound was very useful in orienteering the diagnosis and insist on the medical history. Serology resulted positive for B. henselae and at the end the family remembered that 6 months before the child was scratched by a kitten.