Acne Vulgaris Tổng quan về bệnh

Giới thiệu

Acne vulgaris is chronic inflammatory dermatosis which is notable for open and/or closed comedones (blackheads and whiteheads) and inflammatory lesions including papules, pustules, nodules, and cysts.

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Dịch tễ học

In 2024, a worldwide global study on acne vulgaris demonstrated an overall prevalence at 20.5%, with the highest rates noted among individuals 16 to 24 years of age. A study based on the data collected from the Global Burden of Disease Study 2021 conducted from 1990 to 2021 on acne vulgaris prevalence, incidence, and disability-adjusted life years concluded an increase in cases worldwide over the past three decades by an average of 0.43% annually. Gender also played a role in the reported prevalence of acne, with young women having a higher prevalence rate by 25% compared to young men. Among the different regions, Western Europe, high-income Asia Pacific, and East Asia had the highest age-standardized prevalence rate. While Central Europe, Tropical Latin America, and Central Asia had the lowest age-standardized prevalence rate. In the United States, it is the most prevalent chronic skin disease with 50 million people being affected.

Among Asian countries, a community-based study showed that 88% of adolescents aged 13 to 19 years in Singapore suffer from acne. In different population age groups in China, the prevalence of acne ranges from 51.3-62.7%, while different studies in Malaysia showed the prevalence of acne at 60-68%. 

Sinh lý bệnh

Acne vulgaris involves follicular hyperkeratinization, microbial colonization with Cutibacterium acnes (previously known as Propionibacterium acnes), sebum production, complex inflammatory mechanisms involving both innate and acquired immunity, neuroendocrine mechanisms, and genetic and non-genetic factors. Excessive sebum production is caused by increased androgens or an increase in the sensitivity of sebaceous glands to androgens. Sebum overproduction combined with abnormal follicular keratinization leads to blockage of the pilosebaceous units, which in turn leads to the formation of comedones. Subsequent rupture and inflammatory reactions to both the rupture and C acnes lead to the development of inflammatory lesions (eg papules, pustules, nodules).

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Yếu tố nguy cơ

Risk factors for the development of acne include increasing age during adolescence, family history of acne, and oily skin type. Adolescent acne is due to the hormonal surges as a child transition into adulthood while post-adolescent acne is due to many contributing factors.

Phân loại

Types of Acne Lesions

• Comedonal (non-inflammatory): Can be closed (whitehead) or open (blackhead) lesions
• Papulopustular (inflammatory)
  • Papule: A small bump <5 mm in diameter
  • Pustule: A small bump with a core of purulent material
• Nodular (inflammatory) and nodulocystic
  • Represents severe acne, manifested as nodules, cysts, and deep pustules >5 mm in diameter
  • Conglobate acne is a severe form of nodular acne where the lesions are firm, inflamed, and painful, measuring >10 mm

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