High prevalence of abscesses and cellulitis among community-recruited injection drug users in San Francisco.

The prevalence of and risk factors for abscesses and cellulitis were investigated among a community sample of injection drug users (IDUs). Participants were interviewed, and those with symptoms were examined. Of 169 IDUs, 54 (32%) had abscesses (n=35), cellulitis (n=5), or both (n=14); 27% had lanced their own abscesses; and 16% had self-treated with antibiotics they purchased on the street. IDUs who skin-popped (injected subcutaneously or intramuscularly) were more likely to have an abscess or cellulitis than those who had injected only intravenously (odds ratio, 4.9; 95% confidence interval, 2.2-11). The likelihood of abscesses and cellulitis increased with frequency of skin-popping and decreased with increasing duration of injection drug use. Abscesses are extremely prevalent among IDUs in San Francisco. Skin-popping is a major risk factor, and self-treatment is common.