Skin Infections in People Who Inject Drugs

The ongoing opioid epidemic has led to a staggering loss of life in the United States, with ever-increasing rates of overdose and associated deaths reported by the Centers for Disease Control and Prevention.¹ The related surge in injection drug use has also led to a range of other health crises, including increasing rates of infectious diseases such as HIV, HCV, and HBV.²

In addition, a sizable body of research has shown various skin and soft tissue infections (SSTI) that often affect people who inject drugs (PWID). According to crude estimates drawn from national public health data, roughly 98,000 hospitalizations and emergency department (ED) visits related to SSTI in PWID occur annually in the United States.³

The bacterial and fungal infections found in PWID primarily stem from skin and mouth flora at the site of injection. Staphylococcus aureus is the most common bacterial pathogen leading to SSTI in this population.² In a study of 1,002 PWID who were admitted to the hospital or ED in New York, clinical cultures revealed bacterial and fungal pathogens in 70 patients, specifically S. aureus (80%); streptococci (16%), and Candida spp. (6%).⁴

In a study of more than 17 million hospital admissions that occurred in Florida in recent years, a methicillin-resistant S. aureus (MRSA) diagnosis was 2.4 more likely in patients with vs without opioid dependence (OR, 2.38; 95% CI, 2.33; 2.43, P <.001). Rates of MRSA infections were 4.7% and 2.0% among each group, respectively.⁵

These infections frequently lead to cellulitis and abscesses in PWID and increase the risk for bloodstream infections and multiorgan disease. In a sample of hospitalized patients in Oregon, the number of patients with serious bacterial infection due to injection drug use increased from roughly 2.5% to 8.5% from 2008 to 2018, most commonly among those with opioid use (P<.001). The greatest increase (18-fold) was observed in hospitalizations for bacteremia/sepsis.⁶

 In a systematic review of 37 papers, SSTIs were present in 88.7% of PWID with AA amyloidosis. These patients typically experienced rapid renal deterioration, with premature death from sepsis in some cases.⁷

The substantial morbidity and mortality associated with SSTIs in PWID underscores the critical importance of timely treatment of these infections as well as hygiene education and utilization of harm reduction strategies for opioid use disorders (OUD). Given the predominant role of skin flora in injection-related infections, essential risk reduction measures include washing hands, cleaning the skin before injecting, and avoiding the use of contaminated equipment or nonsterile water for skin cleaning or drug dilution.^4,8

Referral to syringe service programs can help to facilitate several of these needs and further educate patients about harm reduction measures including safe injection practices.⁴ Many experts also emphasize the valuable opportunity to refer patients to treatment with medication for OUD (MOUD; formerly known as medication-assisted treatment) when they present with bacterial and fungal infections due to injection drug use.

In the study of New York patients admitted to the hospital or ED, 97% of PWID who had infections were opioid users. However, only one-half of inpatients and 8% of those seen in the ED were offered MOUD.⁴ By linking patients who inject drugs to MOUD, providers can help to address the underlying OUD while also reducing the risk for recurrent infection.⁸

We gleaned additional clinical insights in an interview with Raja Sivamani, MD, MS, AP, board-certified dermatologist and adjunct associate professor of clinical dermatology at the University of California, Davis, in Sacramento, and Ayurvedic practitioner at Zen Dermatology.

What are the skin infections commonly seen in people who inject drugs?

Some of the common skin infections include Staphylococcus aureus, including resistant strains like methicillin resistant Staphylococcus aureus (MRSA)andGroup A streptococci (GAS), and in severe cases there can be necrotizing fasciitis. In some cases, there can also be infections with gram-negative bacteria or anaerobic bacteria. 

What are your recommendations for providers regarding the treatment of skin infections in this population?

Antibiotics are very important, and the infection site should be assessed for the presence of an abscess to see if that needs to be opened and drained. The antibiotics should cover MRSA if there is evidence for prior colonization with MRSA or if there is suspicion to believe that a MRSA infection might be possible.

In some cases, the antibiotics may need to include coverage of gram-negative bacteria and anaerobic bacteria, especially if the common antibiotics against staphylococcus and streptococcus do not seem to be working. If necrotizing fasciitis is a concern, an urgent surgical consultation is required. 

When appropriate, how do you approach the underlying issue of drug use with patients?

I think it is important to be direct with patients while asking in a non-accusatory way to allow patients to feel comfortable in answering honestly. I will broach the subject if we see characteristic injection scars, wounds, or active infections that are suggestive of drug use. I will have a discussion about the impact of drug use on their health and try to offer local resources for support, and I will frequently work with the primary care provider. 

What are remaining gaps in this area, and what can be done to address these needs?

One of the gaps that remains is access to care. Many times, patients engaging in drug use may not know where to go if they have early signs of infection and may wait until the infection is more serious before going to the emergency room or urgent care. They may have a lack of insurance that can also prevent them from seeking care, and we need to have easily accessible clinics. One example is the Joan Viteri Memorial Clinic that is affiliated with UC Davis which is a free community clinic that frequently treats patients with issues related to IV drug use. 

References

1. Centers for Disease Control and Prevention. Drug overdose deaths. Accessed online July 31, 2021.
2. Sanchez DP, Tookes H, Pastar I, Lev-Tov H. Wounds and skin and soft tissue infections in people who inject drugs and the utility of syringe service programs in their management. Adv Wound Care (New Rochelle). 2021;10(10):571-582. doi:10.1089/wound.2020.1243
3. See I, Gokhale RH, Geller A, et al. National public health burden estimates of endocarditis and skin and soft-tissue infections related to injection drug use: a review. J Infect Dis. 2020;222(Suppl 5):S429-S436. doi:10.1093/infdis/jiaa149
4. Hartnett KP, Jackson KA, Felsen C, et al. Bacterial and fungal infections in persons who inject drugs – Western New York, 2017. MMWR Morb Mortal Wkly Rep. 2019;68(26):583-586. doi:10.15585/mmwr.mm6826a2
5. Smotherman C, Bilello L, Lukens-Bull K, Merten J, Wells S. Opioid dependence and methicillin-resistant staphylococcus aureus (MRSA) colonization or infection in hospitalized patients in Florida: a retrospective study. Int Arch Public Health Community Med. 2019;3:017. doi:10.23937/iaphcm-2017/1710017
6. Capizzi J, Leahy J, Wheelock H, et al. Population-based trends in hospitalizations due to injection drug use-related serious bacterial infections, Oregon, 2008 to 2018. PLoS One. 2020;15(11):e0242165. doi:10.1371/journal.pone.0242165
7. Harris M, Brathwaite R, Scott J, et al. Drawing attention to a neglected injecting-related harm: a systematic review of AA amyloidosis among people who inject drugs. Addiction. 2018;113(10):1790-1801. doi:10.1111/add.14257
8. Baltes A, Akhtar W, Birstler J, et al. Predictors of skin and soft tissue infections among sample of rural residents who inject drugs. Harm Reduct J. 2020;17(1):96. doi:10.1186/s12954-020-00447-3
9. Barocas JA, Gai MJ, Amuchi B, Jawa R, Linas BP. Impact of medications for opioid use disorder among persons hospitalized for drug use-associated skin and soft tissue infections. Drug Alcohol Depend. 2020;215:108207. doi:10.1016/j.drugalcdep.2020.108207