The microbial evaluation of acute cellulitis.

Twenty consecutive patients with acute cellulitis were studied by retrospective chart review. Patients with suffusion and edema, with or without vesicles, were included. Patients with breaks in the skin, with focal suppurations or with concurrent antimicrobial therapy were excluded. In nineteen of the twenty patients, aspirates (95 percent) failed to grow organisms. Pasteurella multocida was grown from subcutaneous aspirate and blood cultures of a single patient; he was immunocompromised by Waldenström's macroglobulinemia and chlorambucil therapy. Two of the nineteen patients with negative aspirate cultures had positive blood cultures, one for type B Hemophilus influenzae and the other for a probably spurious Campylobacter fetus. All twenty patients, including the two immunocompromised patients, responded completely to appropriate empiric antimicrobial therapy. There were no complications of the needle aspirate technique observed. Needle aspiration is indicated early in the course of acute cellulitis in the immunocompromised, the young child with facial cellulitis, those with open wounds, and those who fail to respond to conventional antimicrobial therapy. For the otherwise well patient with intact host defenses, it is of extremely low sensitivity.