[An infant with septic arthritis due toKingella kingae].

BACKGROUND

Kingellakingae is the most frequently found pathogen in septic arthritis in children ≤ 4 years. In contrast to more well-known pathogens, K. kingae usually causes mild arthritis symptoms without high fever or elevated infection markers. In the current (general practitioners') guidelines on septic arthritis in children too little attention is given to the indolent symptoms caused by K. kingae. This could cause a delay in the diagnosis and treatment of children with K. kingae arthritis.

CASE DESCRIPTION: An 11 months old boy presented to the general practitioner with 6 days of general malaise, upper airway symptoms and a painful, swollen left knee without fever or preceding trauma. Ultrasound of the knee was normal. Blood samples showed mildly elevated infection markers. K. kingae DNA was isolated using an oropharyngeal PCR and the diagnosis K. kingae septic arthritis was made. Antimicrobial therapy was initiated and resulted in a full recovery.

CONCLUSION

In children ≤ 4 years with joint symptoms a septic arthritis caused by K. kingaeshould be considered, even if in the absence of evident symptoms of infection.