How are bacterial skin cultures performed, and when are they useful?

Bacterial cultures are useful when active infection of the skin is suspected. Bacterial cultures demonstrate high yields in superficial infections such as impetigo, ecthyma, and infected ulcers, and lower yields in cellulitis. When culturing superficial infections, the involved area should first be cleaned with an alcohol pad and then thoroughly swabbed. A higher concentration of bacteria may be found at the point of maximal inflammation. The best results in cellulitis are obtained when the leading edge is injected with nonbacteriostatic saline using a 20-gauge needle mounted on a tuberculin syringe. The aspirate may be sent for culture while still in the syringe if it can be taken to the laboratory immediately, or the aspirated material may be submitted in a bacterial culturette.