From the Guidelines
Acne is a disease, not an infection, though bacteria can play a role in its development. The key difference is that a disease is any condition that impairs normal functioning, while an infection specifically results from pathogens invading and multiplying in body tissues. Acne is primarily caused by excess oil production, clogged hair follicles, inflammation, and bacteria (Propionibacterium acnes) 1. While these bacteria contribute to acne by causing inflammation, they naturally live on the skin and don't "invade" in the way infectious agents do. This is why acne is classified as an inflammatory skin disease rather than an infection.
Causes and Classification
The multifactorial pathogenesis of acne involves follicular hyperkeratinization, microbial colonization with Cutibacterium acnes, sebum production, complex inflammatory mechanisms involving both innate and acquired immunity, neuroendocrine mechanisms, and genetic and nongenetic factors 1. Risk factors for acne development include increasing age during adolescence, family history of acne, and oily skin type.
Treatment Approaches
Treatment typically targets the multiple causes: topical retinoids (like tretinoin) to prevent clogged pores, benzoyl peroxide to kill bacteria, and sometimes antibiotics (like doxycycline) to reduce inflammation and bacterial growth 1. For severe cases, oral isotretinoin may be prescribed. Understanding acne as a disease helps explain why treatment approaches are multifaceted rather than simply focused on eliminating bacteria as would be the case with a true infection.
Importance of Limiting Systemic Antibiotic Use
It's also important to limit the use of systemic antibiotics in treating acne due to concerns about antibiotic resistance and disruption of the microbiome 1. Alternative approaches include the use of novel topical agents, dietary modification, laser and light-based treatments, and systemic medications such as spironolactone, combined oral contraceptives, and oral isotretinoin.
Quality of Life Impact
Acne has a significant impact on emotional functioning, social functioning, relationships, leisure activities, daily activities, sleep, school, and work, comparable to that of chronic conditions such as asthma, psoriasis, and arthritis 1. Therefore, managing acne effectively is crucial not only for reducing its physical symptoms but also for improving the patient's quality of life.
From the FDA Drug Label
In severe acne, doxycycline may be useful adjunctive therapy. In severe acne, minocycline may be useful adjunctive therapy.
Acne is not explicitly stated as an infection in the provided drug labels. However, the fact that antibiotics like doxycycline and minocycline are used as adjunctive therapy in severe acne suggests that pathogens may be involved.
- The key difference between a disease and an infection is that an infection is caused by a pathogen, such as a bacterium, virus, or fungus, while a disease can have various causes, including genetic, environmental, or lifestyle factors.
- In the case of acne, it is considered a disease with multiple factors contributing to its development, including hormonal, genetic, and environmental factors.
- While pathogens like Propionibacterium acnes (P. acnes) may play a role in the development of acne, it is not solely an infection.
- The use of antibiotics in acne treatment is likely aimed at reducing the population of P. acnes and inflammation, rather than treating an infection in the classical sense 2 3.
From the Research
Definition of Acne
- Acne is a chronic inflammatory disease of the pilosebaceous unit, resulting from androgen-induced increased sebum production, altered keratinisation, inflammation, and bacterial colonisation of hair follicles 4.
- It is not strictly an infection, but rather a complex condition involving multiple factors, including bacterial colonization by Propionibacterium acnes (now known as Cutibacterium acnes) 4, 5.
Disease vs. Infection
- A disease is a disorder of structure or function in a human, especially one that produces specific signs or symptoms or that affects a specific location and is not simply a direct result of physical injury 6.
- An infection, on the other hand, is the invasion and multiplication of microorganisms such as bacteria, viruses, and parasites that are not normally present within the body 7.
- In the case of acne, while bacteria such as Cutibacterium acnes play a role in its development, it is considered a disease rather than a simple infection 4, 5.
Treatment of Acne
- Treatment for acne typically involves a combination of topical and systemic therapies, including retinoids, benzoyl peroxide, antibiotics, and hormonal agents 7, 6, 8.
- The goal of treatment is to reduce inflammation, prevent scarring, and improve quality of life 6, 5.
- In severe cases, oral isotretinoin may be used, but its use is limited by potential side effects and teratogenicity 6, 8, 5.