Blood Cultures (Still) Not Indicated for Uncomplicated Skin Infections

Blood cultures are positive in about 4% of all comers with cellulitis. In a prospective, observational, single-center study, researchers assessed the rate of positive blood cultures in admitted patients with skin and soft tissue infections, and in the subsets with injection drug use or fever. Importantly, the investigators did not determine who would undergo blood cultures.

Of 246 admitted patients with skin infection, 86 (35%) had blood cultures, and 7.0% of cultures were positive. Among the 29 blood-cultured patients who were febrile, 3.5% had positive blood cultures. Of 101 admitted patients who were injection drug users, 46% had blood cultures, and of these, 8.7% were positive.