Septic arthritis in early infancy.

Septic arthritis in infants who are less than two months of age is a rare condition. During a recent seven-year period, eighteen cases of infantile septic arthritis were diagnosed at Mackay Memorial Hospital. The ratio of males to females was 1.6:1. The most common symptoms were crying during diaper change, and an immobile and swollen joint. Nonspecific symptoms such as fever, poor appetite and lethargy were uncommon. The hip was the most commonly affected joint with the knee taking second place. Ten cases (55%) demonstrated concomitant osteomyelitis. A bacterial etiology was established in 16 cases (88%). The predominant pathogens were S. aureus (5 cases) followed by group B streptococcus (4 cases). Total parenteral nutrition was the predisposing factor of infection in 4 of the 5 S. aureus arthritis cases. The duration of treatment ranged from 21 to 44 days. Two patients developed sequelae: namely discrepancies in leg length, and a limping gait. Early diagnosis and prompt antibiotic treatment are crucial elements in the prevention of disabling and catastrophic sequelae in young infants who have septic arthritis. In addition, open drainage is highly recommended in hip and shoulder arthritis.