Acne conglobata: A very severe type of acne in which nodules are connected beneath the skin surface to other nodules or acne lesions.

Acne mechanica: Form of acne that develops in response to heat, covered skin, constant pressure, and/or repetitive friction against the skin.

Acne Vulgaris: The medical term for common acne, which is characterized by the presence of one or more of the following: blackheads, whiteheads, papules and pustules.

Androgenic: Referring to the hormones that stimulate the sebaceous glands to create sebum.

Androgens: Hormones that stimulate sebaceous glands in addition to other effects on the body. Present in both males and females, androgens are responsible for physical maturation in males and therefore occur in much higher levels in males. Males tend to have more severe acne than females.

Antimicrobial: Agent, such as a medication, that kills or eliminates microorganisms.

Azelaic acid: This acid naturally occurs in the body and is used to treat both inflamed and non-inflammatory conditions. It has few side effects, the most common being skin irritation. Azelaic acid is used to kill P. acnes, the bacteria that causes acne. It also reduces peeling and inflammation.

Benzoyl Peroxide: A bleaching agent that kills bacteria and ranges in strength from mild to strong. It comes in various prescription and over the counter creams, gels, lotions, and washes. Benzoyl peroxide has no anti inflammatory properties. While effective in healing acne, if used incorrectly, it an lead to skin burns and bleached hair.

Blackhead: A non-inflammatory acne lesion that is filled with excess oil and dead skin cells. Blackheads are also called “open comedomes” because the surface of the skin remains open.

Clindamycin: Much like azelaic acid, clindamycin is effective because it kills P. acnes and reduces inflammation. It is usually side effect free, but has been shown to cause skin dryness and irritation in some people.

Chloracne: Rash characterized by many comedones that develops from exposure to chlorinated chemicals or herbicides.

Closed comedo: A whitehead; a non-inflammatory comedo with white center.

Comedones: Comedones are commonly referred to as blackheads and whiteheads, and are the least severe types of acne. A comedo forms when residual skin oil, makeup, dirt, dead skin, and small hairs impact a sebaceous follicle and prevent the pore from functioning correctly. The result is a small impaction that is neither red nor painful. If the pore is open, the comedo will be dark in appearance and is thus called a blackhead. If the pore is closed, than the comedo is referred to as a whitehead, and is flesh-colored in appearance.

Comedogenic: Likely to cause comedones.

Cysts: Usually occurring in conjunction with nodules, cysts are considered severe acne lesions and are usually very painful. They penetrate the skin deeply, and usually result in scarring. Filled with bacteria, dead skin cells, and white blood cells, cysts are often severely inflamed and almost always cause scarring. When a nodule and a cyst occur together, it is often referred to as nodulocystic. Nodulocystic conditions are often only treatable with isotretinoin.

Dermatologic surgery: Deals with the diagnosis and treatment of medically necessary and cosmetic conditions of the skin, hair, nails, veins, mucous membranes and adjacent tissues by various surgical, reconstructive, cosmetic and non-surgical methods. This includes laser surgery, cryosurgery, chemical surgery, aspirational surgery and excisional surgery. The purpose of dermatologic surgery is to repair and/or improve the function and cosmetic appearance of skin tissue

Follicle: The tiny shaft in the skin through which a hair grows, and sebum is excreted from sebaceous glands to the surface of the skin.

Hormones: Chemical substances produced by the body that, depending on the hormone, govern many body processes. Certain hormones cause physical maturation during puberty. These are the ones implicated in acne.

Inflammatory: A word that means “causing inflammation.” In acne, “inflammatory” is usually used to describe lesions that are inflamed by chemical reactions or bacteria in clogged follicles.

Intersional Corticosteroid Injection: Corticosteroids have a long history of reducing inflammation in a wide array of problems. If severe acne, such as a nodule of cyst, progresses to a point that a rupture is suspected, a dermatologist may apply a diluted shot of corticosteroid in hopes of preventing rupture and the resulting scarring.

Isotretinoin: Potent systemic medication used to treat severe forms of acne. Due to potential birth defects, a woman must not take this medication while pregnant or breast feeding and must not become pregnant while taking isotretinoin.

Keloid: Large raised scar that spreads beyond the size of the original wound.

Lipids: Oily substances that include things like fats, oils and waxes. Sebum is made up of lipids. A particular kind of lipid, free fatty acids, are irritating to the skin.

Macule: A macule is the result of a healed acne lesion. It consists of a red flat patch of skin with a defined border, and may be present for up to several weeks before disappearing. Macules may appear like a grouping of inflamed pustules or psoriasis. New lesions may appear atop the macules of previous infections, and can lead to scarring if scratched open.
Melanin: Substance that gives hair and skin its color.

Micro comedo: The first stage of comedo formation; a comedo so small that it can be seen only with a microscope.

Nodulocystic acne: A severe form of acne that is characterized by numerous deep, inflamed bumps (nodules) and large, pus-filled lesions that resemble boils (cysts). The nodules tend to be tender when touched and feel firm. The severe inflammation can cause the acne to become very red or even purple. Scarring often results when the acne heals.

Nodules: Nodules are the natural progression of a papule. They appear very similar to papules, but are inflamed and penetrate deep into the skin. They may result in tissue damage and can lead to severe scarring. Pustules are often very painful; pustules are considered a severe form of acne, and can be difficult to cure.

Noncomedogenic: Not likely to cause comedones.

Non inflammatory: In acne, comedones that are not associated with redness in the skin.

Open comedo: (A blackhead) a noninflammatory comedo with a dark top and firmly packed contents.

Papule: An inflammatory comedo that resembles a small, red bump on the skin.

Papulopustular: A type of acne characterized by the presence of papules and pustules.

Post-inflammatory hyperpigmentation: Excessive skin darkening at places where the skin was inflamed.

Propionibacterium acnes (P. acnes): A normal resident on the skin,
P. acnes will multiply rapidly in clogged hair follicles where sebum is trapped.

Puberty: The time of life when a child begins the physical maturation process toward adulthood. Onset is usually in the early teens and is accompanied by a large increase in hormone production.

Pustule: Pustules, while similar in appearance to macules, are active infections of the skin that consists of dead skin cells and bacteria. These lesions are spherical in appearance and are filled with pus. Often reddish in color, pustules may be painful and will break open easily if scratched or bumped. Pustules will likely heal without other aid; however, some will develop into cysts.

Retinoid: A natural or synthetic substance derived from vitamin A.

Sebaceous glands: Glands in the skin that produce an oily substance called sebum–these glands are the sites of acne lesions. Sebaceous glands are attached to hair follicles and are found mostly on the face, neck, back and chest.

Sebum: The oily substance produced by sebaceous glands.

Steroid acne: Acne that develops from long-term use of corticosteroid medications. Since this condition can develop, corticosteroid medications are prescribed for a limited time.

Systemic therapy: Treatment that consists of taking medication internally, such as in pill form or by injection or infusion.

White blood cells: Components of the blood that help fight off infections.

Whitehead: An acne lesion that forms when oil and skin cells block the opening of a hair follicle. For this reason, whiteheads are called “closed comedomes.”