Artritis séptica de rodilla por Kingella kingae: Presentación de dos casos clínicos

Abstract

Kingella kingae is a common colonizer of the oropharynx in young children. 
Although most colonization is asymptomatic, it can lead to invasive infection. This microorganism is increasingly recognized as a cause of osteoarticular infections in children. The limited data of septic arthritis due to K. kingae and the difficulty to identify this organism in routine cultures, can delay the diagnosis and treatment.
Two cases of infants with septic arthritis by K. kingae diagnosed by PCR are described.
The first one is about a 20-month-old woman with initial suspicion of transient synovitis of the right hip, who came to the emergency department with limping in the last 10 days. She is admitted to hospital because of fever and inflammation on the right knee for 48 hours. We initiated empirical treatment with cefotaxime and cloxacillin after diagnosis of septic arthritis. Positive PCR for K. kingae was obtained in joint fluid.
The second case is about a 20-month-old male who came to the emergency room due to pain, swelling and limitation to left knee flexion, 2-3 weeks of evolution, accompanied by fever for the last 24 hours (38.5ºC). He had the antecedent of catarrhal picture previously. He had been admitted to hospital the previous week because of the same symptoms, with blood and joint fluid exams without alterations. He is admitted again with empirical treatment with cloxacillin and cefotaxime after repeating the laboratory exams. K. kingae was identified by PCR in the second sample of joint fluid.
Both cases presented had good evolution without subsequent sequels.