Abscess formation as a complication of parenteral methylphenidate abuse

Case reports of five patients suffering from either skin abscesses or cellulitis following parenteral methylphenidate abuse are presented. Four patients had similar lesions consisting of abscesses or cellulitis which demonstrated typical signs and symptoms of an infective process and were treated with local symptomatic therapy, incision and drainage if indicated, and systemic antibiotics. The fifth patient suffered from a circular, necrotic, nonpurulent ulcer on the dorsum of the right foot which produced no local or systemic toxic effects. Attempts to culture a responsible organism yielded Streptococcus viridans, an organism which is normal flora of the skin and, although opportunistic, is generally considered nonpathogenic. These cases further substantiate the belief that local vasospasm, chemical irritation, or both, produced by the methylphenidate solution may primarily cause a necrotic ulcer susceptibble to secondary bacterial infection.