Antibiotic resistance: It is also in our skin!
We really need antibiotics. We need them, for treating and preventing bacterial infections. But over time, bacteria tend to become resistant to the antibiotics we use against them, and misusing the antibiotics accelerates this process. This means that some diseases that were before easily treated now are not so easy -sometimes even impossible- to treat anymore, because the bacteria that causes them are resistant to our weapons (1). These bacteria are called superbugs, and they kill 33.000 people in Europe every year (2).
Antibiotics are widely used to treat and prevent bacterial infections.
We really do need new antibiotics. Because we are running out of them. WHO claims that most of the antibiotic drugs that are on clinical trials are just modifications of the ones we already have, so they are only a short-term solution (3). If we do not solve this problem, at some point, we will not have a way to combat common infections.
In dermatology, antibiotics are widely used to treat skin infections, including acne, rosacea, impetigo, folliculitis… This recurrent use of antibiotics leads to a potential overuse, increasing the risk of antibiotic resistance. As an example, topical mupirocin has been often used to treat skin infections that are resistant to other antibiotics. Even the application of a low concentration of topical antibiotics can produce resistances, such as the case of the development of mupirocin-resistant strains of MRSA (methicillin-resistant Staphylococcus aureus). Among the measures that have been proposed to avoid the raise of resistances, we find the development of precise history and diagnostic laboratory and culture studies, along with the prescription of targeted therapy in cases when the microorganism responsible is identified. (4)
From all skin diseases, acne vulgaris has emerged as one of the main concerns regarding the increase of antibiotic resistances. After all, more than 80% of adolescents have acne, and antibiotic treatment is widely used against Cutibacterium acnes (formerly called Propionibacterium acnes, acne related bacteria). However, acne is not only an infectious disease: inflammation plays also a very important role on the pathogenesis of acne. This way, eliminating C. acnes does not necessarily eliminate acne. Accordingly, it has been proposed that antibiotics might be working on acne by inhibiting inflammation.
If we look at the overall incidence of antibiotic resistant C. acnes, we see a huge increase from 20% in 1978 to 62% in 1996. This incidence is not the same everywhere: the countries that restrict the use of antibiotics to treat acne have the lower levels of resistance (5). Resistant C. acnes does not only affect the patient under antibiotic treatment, but also can be found in untreated people in contact with the patient. Moreover, topical antibiotics increase the resistance in other bacteria commonly found in skin, like S. aureus, related to community associated infections (6). Oral antibiotics for acne, in turn, have been reported to cause an increase of upper respiratory tract infections by a resistant Streptococcus pyogenes (7).
Antibiotics against acne are widely used, but the resistances are more prominent where they are more prescribed.
The raising concern on antibiotic resistance in acne has driven the Global Alliance to Improve Outcomes in Acne to publish different treatment strategies according to the acne state. When antibiotics are the first choice, they are suggested to be administered in combination either with topical retinoids or benzoyl peroxide in order to minimize the resistances (5).
Time is running out. Resistances increase and new antibiotics are still not coming (enough). The weapons we have now to treat infections have to remain valid for some time, so we must use them wisely. Dermatology, and specially acne, plays an important role in this issue because of its widespread use of antibiotics. It is essential to improve acne treatments, in order to ensure patients improvement, while resistances are avoided.
(1) Antibiotic resistance https://www.who.int/news-room/fact-sheets/detail/antibiotic-resistance (accessed Apr 19, 2020).
(2) Superbugs kill 33,000 in Europe every year - CNN https://edition.cnn.com/2018/11/06/health/superbugs-kill-33000-in-eu-scli-intl/index.html (accessed Apr 19, 2020).
(3) The world is running out of antibiotics, WHO report confirms https://www.who.int/news-room/detail/20-09-2017-the-world-is-running-out-of-antibiotics-who-report-confirms (accessed Apr 19, 2020).
(4) Chon, S. Y.; Doan, H. Q.; Mays, R. M.; Singh, S. M.; Gordon, R. A.; Tyring, S. K. Antibiotic Overuse and Resistance in Dermatology. Dermatol. Ther. 2012, 25 (1), 55–69. https://doi.org/10.1111/j.1529-8019.2012.01520.x.
(5) Walsh, T. R.; Efthimiou, J.; Dréno, B. Systematic Review of Antibiotic Resistance in Acne: An Increasing Topical and Oral Threat. The Lancet Infectious Diseases. Lancet Publishing Group March 1, 2016, pp e23–e33. https://doi.org/10.1016/S1473-3099(15)00527-7.
(6) Adler, B. L.; Kornmehl, H.; Armstrong, A. W. Antibiotic Resistance in Acne Treatment. JAMA Dermatology. American Medical Association August 1, 2017, pp 810–811. https://doi.org/10.1001/jamadermatol.2017.1297.
(7) Sinnott, S. J.; Bhate, K.; Margolis, D. J.; Langan, S. M. Antibiotics and Acne: An Emerging Iceberg of Antibiotic Resistance? British Journal of Dermatology. Blackwell Publishing Ltd December 1, 2016, pp 1127–1128. https://doi.org/10.1111/bjd.15129.