Why is Clindamycin (clindamycin) used to treat acne vulgaris if it is not considered a bacterial infection?

From the Guidelines

Clindamycin is used in acne treatment because it has both antimicrobial and anti-inflammatory properties, addressing the complex pathophysiology of acne which involves bacteria, inflammation, and dysfunction of the pilosebaceous unit. While acne vulgaris is not primarily an infection, it does involve bacteria in its pathophysiology. In medicine, an infection is defined as the invasion and multiplication of pathogenic microorganisms in body tissue that causes cellular injury and triggers an immune response 1. Acne doesn't fit this definition because it's primarily a disorder of the pilosebaceous unit (hair follicle and oil gland) involving excess sebum production, abnormal keratinization, inflammation, and colonization by Cutibacterium acnes (formerly Propionibacterium acnes) 1. C. acnes is actually a normal skin commensal that becomes problematic when trapped in follicles. Clindamycin works in acne by reducing the C. acnes population and suppressing inflammation, addressing two components of acne's complex pathophysiology. The bacteria in acne aren't invading tissue as in a true infection; rather, they're contributing to inflammation in an already dysfunctional follicle. This is why acne is classified as an inflammatory disorder rather than an infectious disease, even though antimicrobials are part of its treatment.

Key Points

• Acne vulgaris is a common skin condition affecting a significant portion of the global population, with a substantial impact on quality of life 1.
• The pathogenesis of acne is multifactorial, involving follicular hyperkeratinization, microbial colonization, sebum production, and complex inflammatory mechanisms 1.
• Clindamycin, along with other topical and oral treatments, is recommended for the management of acne based on its antimicrobial and anti-inflammatory properties 1.
• The use of systemic antibiotics, including clindamycin, should be limited to reduce the development of antibiotic resistance and other complications, and should be used concomitantly with benzoyl peroxide and other topical therapies when possible 1.

Recommendations

• Topical clindamycin is recommended for the treatment of acne due to its efficacy in reducing bacterial colonization and inflammation.
• Combination therapy with multiple mechanisms of action is recommended for optimal treatment outcomes 1.
• Limiting systemic antibiotic use and combining with topical therapies is a good practice statement for the management of acne 1.

From the FDA Drug Label

The mechanism of action of clindamycin in treating acne vulgaris is unknown. Clindamycin is active in vitro against most isolates of Propionibacterium acnes; however, the clinical significance is unknown.

• Acne vulgaris is treated with clindamycin due to its activity against Propionibacterium acnes, a type of bacteria that plays a role in the development of acne.
• The term infection in medicine typically refers to the invasion and multiplication of microorganisms such as bacteria, viruses, and parasites that are not normally present in the body.
• Acne vulgaris does not fit the traditional definition of an infection as it is not caused by the invasion of a pathogen, but rather by a combination of factors including overproduction of sebum, clogged pores, and the presence of Propionibacterium acnes.
• The use of clindamycin in acne treatment is likely due to its ability to reduce the population of Propionibacterium acnes, which contributes to the development of acne lesions 2.

From the Research

Definition of Infection in Medicine

• In medicine, an infection is typically defined as the invasion and colonization of a host organism's body tissues by disease-causing agents, such as bacteria, viruses, or other microorganisms.
• The presence of these microorganisms can lead to a range of symptoms and diseases, depending on the type of infection and the affected area of the body.

Acne Vulgaris and Infection

• Acne vulgaris is a skin condition characterized by the occurrence of comedones (blackheads and whiteheads), pimples, and sometimes cysts or nodules.
• While acne is not typically considered a traditional infection, it is associated with the presence of certain bacteria, such as Cutibacterium acnes (C. acnes), which can contribute to the development and severity of acne lesions 3, 4, 5.
• The use of antibiotics, such as clindamycin, in the treatment of acne suggests that there is a bacterial component to the condition, even if it does not fit the traditional definition of an infection.

Use of Clindamycin in Acne Treatment

• Clindamycin is a highly effective antibiotic that has been widely used to treat acne vulgaris, particularly in combination with other agents such as benzoyl peroxide 3, 4, 5, 6.
• The anti-inflammatory properties of clindamycin may also play a role in its therapeutic activity in acne treatment, in addition to its antimicrobial effects 7.
• The use of clindamycin in acne treatment is supported by current practice standards and clinical evidence, which demonstrate its efficacy in reducing inflammation and preventing the growth of C. acnes 3, 4, 5, 6.