Imaging features of soft-tissue infections and other complications in drug users after direct subcutaneous injection.

Drug abuse is a serious problem, both globally and at a local level, with more than 13,400 opiate abusers in Dublin, Ireland, alone. Infectious complications are responsible for 60-80 per cent of hospital admissions of IV drug users. In 2000, in the United Kingdom and Ireland, fatalities associated with soft-tissue inflammation and severe systemic sepsis were linked to 'skin popping' (injection of drugs into the skin and subcutaneous tissues rather than directly into a vein). Clostridium species were implicated in the pathogenesis. Superficial infection may progress to more widespread local or distant disease. Primary soft-tissue infections in IV drug users include cellulitis, abscess, myositis, pyomyositis, and necrotizing fasciitis. Secondary effects of IV drug use include septic arthritis and tenosynovitis, secondary osteomyelitis, vascular complications, soft-tissue ulceration, and fistula formation. In this review, the range of complications caused by skin popping that may develop will be shown. Early imaging to define disease extent and complications is important because clinical deterioration can be precipitous