What is Acne?

Acne Vulgaris

Acne is the common name for acne vulgaris. Vulgaris, as in acne vulgaris, means ordinary, being of the usual type, common.

Acne is a skin condition that occurs when the tiny holes in the skin - called pores - become clogged. These pores connect to oil glands (*sebaceous glands) under the skin. These glands make an oily substance called *sebum. The pores connect to the glands by a canal called a follicle. Inside the follicles, oil carries dead skin cells to the surface of the skin, helping to keep the skin lubricated and prevent drying of tissues. A thin hair also grows through the follicle and out to the skin. When the follicle of a skin gland clogs up, a pimple grows.

Anyone can get acne, but it is most common in teenagers and young adults. Acne affects the areas of skin with the most sebaceous follicles. Acne *lesions occurs mostly on the face, neck, back, chest and shoulders, but may also occur on the trunk, arms, legs, and buttocks. It is the most common skin disease.

Although acne is usually not a serious health threat, it can be a source of significant emotional distress. There is mild acne, moderate to severe inflammatory acne, severe acne, and very severe acne. Severe acne can lead to disfiguring and permanent scarring.

Acne Lesion Types

There are two major types of acne lesions: noninflammatory and inflammatory. Although most drug products for acne are intended for the broad indication of acne vulgaris, some products have been developed that only target one of these two specific subsets of acne vulgaris lesions.

• Noninflammatory Lesions of acne are the open (blackheads) or closed (whiteheads) comedones (plural for comedo). Closed comedones may be more difficult to detect visually and may require stretching of the skin to aid in visualization. These lesions, especially closed comedones, may be precursors to the larger inflammatory lesions and therefore are of clinical importance.
• Inflammatory Lesions are divided into papules, pustules, and nodules/nodulocystic lesions, depending on the severity and location of the inflammation within the *dermis. The papules and pustules have surrounding halos of erythema (redness of the skin) allowing for their characterization as inflammatory. Nodules are typically erythematous and often tender and/or painful. Additionally, they are deep-seated in the skin (centered in the dermis or *subcutis). Nodules have been defined as being greater than 5 mm in diameter. The borders of these lesions may be difficult to determine because of the associated erythema/inflammation.

Acne vulgaris is primarily a disease beginning with and extending beyond puberty, but can persist past the third decade of life. Although acne vulgaris affects both genders (male and female), severity may be greater in males. The severity of acne vulgaris - the number of lesions, the type of lesions, the size of the lesions, amount of inflammation, and scarring - can vary in each individual person. Acne vulgaris occurs in all races and across the United States.

A variety of drug products, topical and *systemic, are currently available to treat acne.

Definitions For This Page - In Alphabetical Order

*Dermis
Pronounced - DER-mis
The second layer of skin, the dermis, is located under the *epidermis. The dermis is sensitive skin, which contains nerve endings, sweat glands, sebaceous glands, and hair follicles. Also called corium or derma.

*Epidermis
Pronounced - ep-i-DER-mis
The first layer of skin, the epidermis, is the outside layer of skin that covers the body surface. This is where the melanin-producing melanocytes are, and where a suntan occurs. The epidermis is a tough thick protective layer of skin (especially on the palms of the hands and the soles of the feet), protecting the body from the environment. The epidermis layer is made up of five sublayers that work together to continually rebuild the surface of the skin. Also called cuticle.

*Lesion
An infected or diseased area of skin. Doctors call acne "acne lesions".

*Sebaceous Glands
Pronounced - suh-bay-shus glands
Glands in the skin that produce an oily substance called sebum, to lubricate the skin, keeping the skin soft and smooth. Sebaceous glands are attached to hair follicles. If the sebaceous glands make too much sebum, mixed with dead skin cells, this can plug our pores and cause acne.

*Sebum
Pronounced - see-bum
The oily substance produced by sebaceous glands.

*Subcutis
The third layer of skin, known as the subcutis or hypodermis, is a fatty layer of subcutaneous tissue located under the epidermis and dermis layers of skin.

*Systemic
Pronounced - sis-TEH-mik
Affecting the whole body.

References:
U.S. Department of Health and Human Services
Food and Drug Administration
Center for Drug Evaluation and Research (CDER)
September 2005
www.fda.gov/