Acne is a common inflammatory skin condition in which hair follicles become blocked by a combination of sebum (oil), dead skin cells, and subsequent inflammatory changes. It is often described as a multifactorial disorder involving follicular occlusion, altered sebum production, inflammation, and interactions with skin microorganisms. Acne most frequently affects areas with relatively higher densities of sebaceous (oil) glands, including the face, chest, back, and shoulders. Hormonal influences are a major contributing factor, particularly during puberty, when androgen levels rise and sebum production often increases. Acne can also occur in childhood and adulthood, with risk and severity shaped by genetics, hormonal fluctuations (including menstrual-related changes), stress, and certain medications such as corticosteroids or some hormonal agents. Skin and hair products may contribute in some individuals, especially if they are oily or otherwise promote follicular blockage.

Acne commonly presents with a mixture of non-inflammatory and inflammatory lesions. Non-inflammatory lesions include comedones, such as blackheads (open comedones) and whiteheads (closed comedones), which arise from plugging of the follicle. Inflammatory lesions may appear as red bumps (papules) or pus-containing spots (pustules), and more severe disease can involve deeper, painful nodules or cyst-like lesions. Symptoms can include tenderness, soreness, and sometimes itchiness, and lesions may recur in patterns that reflect ongoing follicular inflammation. After lesions resolve, some people develop post-inflammatory hyperpigmentation, leaving dark marks that fade over time. Scarring can occur in more severe or long-lasting forms, and the visible nature of acne may contribute to psychological distress in some individuals.

Acne has been recognized for centuries, with early medical descriptions of “pimples” and inflammatory eruptions appearing long before modern dermatologic classification. Over time, clinical observation helped distinguish comedonal and inflammatory patterns, and later advances in microbiology and immunology supported the current understanding of acne as involving multiple interacting processes. The term “acne vulgaris” is widely used for the typical form seen in adolescents and adults, though other acneiform eruptions exist. Epidemiologically, acne is extremely common and is often most noticeable during adolescence, while adult acne is also well documented. The condition is frequently chronic or relapsing, with flares that may correlate with hormonal changes, friction, and individual susceptibility. Terminology and diagnostic framing vary across settings, but the core concept of follicular blockage with inflammation remains central to how acne is described in contemporary medicine.

Note: This description was generated by AI and may contain inaccurate information.

Original Image Producer: Roshu Bangal. Credit: Own work. License: CC BY-SA 4.0. Link to Source: https://commons.wikimedia.org/wiki/File:Acne_vulgaris_on_a_very_oily_skin.jpg .

Original Image Producer: James Heilman, MD. Credit: Own work. License: CC BY-SA 3.0. Link to Source: https://commons.wikimedia.org/wiki/File:Backacne.JPG .