Acne is common in North American white persons. African Americans have a higher prevalence of pomade acne, probably stemming from the use of hair pomades.

During adolescence, acne vulgaris is more common in males than in females. In adulthood, acne vulgaris is more common in women than in men.

Acne or acneiform lesions, such as in neonatal cephalic pustulosis, may be present in the first few weeks and months of life, when a newborn is still under the influence of maternal hormones and when the androgen-producing portion of the adrenal gland is disproportionately large. This neonatal acne tends to resolve spontaneously. However, some neonates require therapy, with topical retinoids sometimes used.

For more on the epidemiology of acne, read here.

The pathogenesis of acne vulgaris is multifactorial. The key factor is genetics. Acne develops as a result of an interplay of the following four factors:

1. Release of inflammatory mediators into the skin

2. Follicular hyperkeratinization, with subsequent plugging of the follicle

3. Follicular colonizationby Propionibacterium acnes

4. Excess sebum production

Research has shown that inflammatory responses actually occur before hyperkeratinization. Cytokines produced by CD4⁺ T cells and macrophages activate local endothelial cells to up-regulate inflammatory mediators, such as VCAM-1, intercellular adhesion molecule 1 (ICAM-1), and human leukocyte antigen (HLA)-DR in the vessels around the pilosebaceous follicle.

Follicular hyperkeratinization involves increased keratinocyte proliferation and decreased desquamation, leading to sebum- and keratin-filled microcomedones.

For more on the pathophysiology of acne, read here.

In comedonal acne, patients develop open and closed comedones, but may not develop inflammatory papules or nodules. Mild acne is characterized by comedones and a few papulopustules. Moderate acne has comedones, inflammatory papules, and pustules. Greater numbers of lesions are present than in milder inflammatory acne. Nodulocystic acne is characterized by comedones, inflammatory lesions, and nodules greater than 5 mm in diameter. Scarring is often evident.

For more on the presentation of acne, read here.

Current consensus recommends a combination of topical retinoid and antimicrobial therapy as first-line therapy for almost all patients with acne. The superior efficacy of this combination, compared with either monotherapy, results from complementary mechanisms of action targeting different pathogenic factors. Retinoids reduce abnormal desquamation, are comedolytic, and have some anti-inflammatory effects, whereas benzoyl peroxide is antimicrobial with some keratolytic effects and antibiotics have anti-inflammatory and antimicrobial effects.

For more on the workup of acne, read here.

Acne can be a very depressing situation. It can alter personality development in the adolescent stage and may facilitate hostility, anger, and antisocial behavior. Associated mood changes and depression have also been reported during treatment. Isotretinoin may heighten feelings of depression and suicidal thoughts. Although a cause-and-effect relationship has not been established, patients should be informed of this potential effect and must sign a consent form acknowledging they are aware of this potential risk. Isotretinoin is also teratogenic and is Category X, with no indication for its use during pregnancy.

For more on the treatment of acne, read here.

Editor's Recommendations Acne Vulgaris Acne Conglobata Acne Fulminans

 

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Any views expressed above are the author's own and do not necessarily reflect the views of WebMD or Medscape.

Cite this article: Robert A. Schwartz. Quiz: What Do You Know About Acne? Medscape. Jan 19, 2016.