Acute sacroiliac joint infection in a rugby player with atopic dermatitis.

In athletes, acute bacterial infection is an unusual cause of pain in the sacroiliac joint. Although an entry site for infection is not always evident, the present case of a 15-year-old rugby player suggests the association between right sacroiliac joint infection and skin lesion of atopic dermatitis (AD) infected with group A streptococcus. Magnetic resonance imaging revealed inflammation around the sacroiliac joint with abscess formation. The infection resolved after a course of antibiotics. Because atopic skin lesion is a potential portal of bacteria, treatment for AD is essential for the prevention of pyogenic arthritis in athletes.