Drugs such as heroin, morphine, cocaine, amphetamine, methamphetamine and certain prescription drugs are injected intravenously and less often via intramuscular or subcutaneous methods. Injection introduces a drug into the bloodstream via a hollow hypodermic needle and a syringe, which breaks the skin. Injection site abscess is one of many health repercussions associated with illicit intravenous drug use or misuse of prescription drugs. A cutaneous abscess is a collection of pus in a confined tissue space, usually caused by a bacterial infection. When abscesses are near the skin, symptoms include local pain, tenderness, warmth and swelling. When they are deep, additional symptoms occur including fever, anorexia, weight loss and fatigue.
Drug-Related Skin Infections
Abscessed infections are associated with a lack of proper hygiene and sterile technique used during the injection process. Skin infections are the leading cause of hospitalization among intravenous drug users. Injection-related wounds, including abscesses and chronic wounds are significant causes of morbidity among this group. Researchers theorize injection-related wounds may be markers for greater addiction-related disease severity and poorer overall health status.
In the 1990s, methicillin-susceptible Staphylococcus aureus (MSSA) and streptococcal species were the most commonly identified microorganisms associated with abscesses in injection drug users. More recently, the emergence of community-associated methicillin-resistant S. aureus (MRSA) has resulted in a significant increase in purulent skin infections, particularly cutaneous abscesses.
Abscess Risk Factors
Vasoconstricting drugs, such as cocaine, injected either alone or in combination with heroin may induce vasospasm and thrombosis, leading to tissue necrosis. Additional possible risk factors for abscesses include skin-popping (defined as direct subcutaneous injection) and kicking, booting or jacking (defined as injecting the drug into the vein, pulling blood into the syringe and then injecting it back into the vein).
Some studies suggest women are at increased risk for developing abscesses, possibly due to difficulty accessing veins, sharing of contaminated injection equipment, injection by someone else and overlapping injection and sexual partners. In a study on 121 daily heroin users, 19.7% had current chronic wounds, while 17.8% reported current abscesses. Among those with an abscess, identified risk factors included being female, skin-popping, injecting with a family member or partner and occasional kicking.
A study on 770 individuals requiring hospitalization for acute bacterial skin infections, found 323 had a cutaneous abscess, and of those, 32% were injection drug users. Compared to non-injection drug users, injection drug users were more likely to have multiple abscesses, prior skin infections and an infection at a site other than the lower extremity. Injection drug users were also more likely to require an incision and drainage procedure in the operating room. Antibiotic therapy was started in the emergency room for 85% of the 323 individuals, with similar regimens among injection drug users and non-injection drug users.
In a study on 858 participants, most of whom had been injecting for more than 20 years, 37% had current abscesses. Injecting for 20 years or more, 90 or more times per day, heroin use and skin-popping in the last 30 days were all associated with an increased risk of abscess. Of the 457 participants reporting a prior lifetime abscess with some type of treatment, 55% were treated by a doctor, 31% reported self-lancing, 5% reported self-medication with illegally purchased antibiotics and 9% self-treated with some form of homeopathic care (e.g., salt-water soak, hot and cold compresses or application of aloe).
If an infection spreads to nearby tissue and throughout the body, this can lead to multiple new abscesses on other skin sites, as well as in the joints. Skin tissue may die as a result of the infection, leading to gangrene and possible skin loss or amputation. When the infection spreads internally throughout the body, this may result in endocarditis (inflammation of the inside lining of the heart). Without early intervention and treatment, endocarditis can be fatal. Long-term antibiotic therapy and hospitalization is required to treat the condition. Infection can also spread to the bone, leading to osteomyelitis. This type of bone infection causes bone pain, fever, nausea, swelling of the extremities and the potential for further infection, resulting in reduced limb or joint function and amputation, in some cases.
Professional Treatment Methods
Uncomplicated abscesses are usually easy to treat; however, large metropolitan counties and hospitals have been burdened by a relatively high prevalence of soft tissue infections among intravenous drug users, often due to delayed treatment. The only consensus on medical treatment of cutaneous abscesses is incision and drainage, but specific recommendations regarding incision type, irrigation, packing, pain management, wound cultures and timing of follow-up visits vary widely.
An ER study found most providers used oral or intravenous analgesia in addition to local anesthetic, linear incisions and packing. The majority of physicians did not use irrigation, order wound cultures or routinely prescribe oral antibiotics unless specific risk factors or physical signs were present. Researchers concluded further research on ideal management of uncomplicated superficial abscesses is needed to create evidence-based guidelines and optimize ER treatment.
While the most optimal way to prevent abscesses is abstinence from drug use, reducing barriers to addiction treatment and implementing prevention programs may be beneficial. An essential component is educating drug users on the risks of needle sharing, skin-popping and kicking. Using alcohol swabs before injecting is an easy and cost-effective means for preventing morbidity and the costs associated with abscess treatment.
Promises Behavioral Health offers a variety of other drug abuse resources, targeted at helping those impacted by substance abuse and addiction better understand the many short and long-term implications.