Dermatology Glossary A

A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - PQ - R - S - T - UV - WXYZ

Abdominoplasty
This operation, also called a "tummy tuck," is a major surgical procedure that flattens the belly by removing excess fat and skin and tightening the underlying muscles. It is usually recommended for individuals who have overhanging skin after weight loss that cannot be treated with liposuction alone.

Ablation
Removal, such as by an ablative laser.

Abscess
An infection that leads to a collection of pus within the tissue. Most abcesses must be treated by draining the infected fluid.

Accutane
Accutane (isotretinoin) is an oral retinoid used for the treatment of moderate to severe acne. (See isotretinoin)

Acne

Acne on foreheadAcne is a very common skin problem that shows up as outbreaks of bumps, papules and/or pustules often called pimples or zits. Acne lesions usually appear on the face, neck, back, chest, and shoulders.

Acne occurs when excess sebum created by the sebaceous glands, builds up beneath the skin within a hair follicle ("pore"). This creates a small bump called a "comedone". A comedone may be referred to as a "blackhead" if the sebum has darkened upon exposure to air. The sebum can become infected with bacteria (p. acnes) which causes the lesion to become red and inflamed. The severity of acne is determined by the extent of the lesions and the degree of inflammation.

Acne can be a source of emotional distress and severe acne, particularly "cystic" or "nodulocystic" acne can lead to permanent scars. Although most people associate the disorder with teenagers, acne can emerge at any age until menopause, especially during times of hormonal flux.

Treatment recommendations are based on the severity of the acne and other variables, and may include benzoyl peroxide, topical retinoids (Differin, Epiduo, Retin A Micro, Tazorac, tretinoin, and Ziana), dapsone (Aczone), topical antibiotics (Duac, Clindagel), oral antibiotics, birth control pills (Yaz, Ortho Tri-Cyclen), isotretinoin (Accutane, Sotret), and various laser and light sources, such as photodynamic therapy (PDT) Learn more about acne

Acute
A condition that has appeared recently or has a short duration. The opposite of "chronic" or long-lasting.

Aging Skin
As the body ages, the skin loses its underlying layers of fat, and the production of collagen and elastin fibers slows down. As a result, the skin becomes thinner, develops fine lines and wrinkles, becomes drier, develops darkened spots, loses underlying fat that can lead to hollowed areas beneath the eyes and cheekbones.

Learn more about aging skin

Aldara
Aldara (imiquimod) Cream 5% is a prescription medication applied to the skin that activates the immune system. It is FDA approved for the treatment of actinic keratoses, superficial basal cell carcinoma (sBCC), and external genital warts.

Learn about Aldara

Alexandrite laser
This is a type of laser used for removing hair and unwanted pigment spots like freckles (ephelides), moles (nevi), and brown birthmarks.

Allergen
A substance that triggers an allergic reaction in people who are sensitive to it. Examples include pollen, dust, latex, certain foods (peanuts), and medications (penicillin, sulfa drugs)

Alopecia, androgenic
Hair loss in men and women from hormonal changes to the hair follicles. In men, it is referred to as "male pattern baldness."

Alopecia areata

Alopecia Areata Alopecia Areata child

This is an autoimmune and often reversible disease in which hair loss occurs in sharply defined patches, usually involving the scalp or beard. In most cases of alopecia areata, hair falls out in small, round patches about the size of a quarter. In many cases, the disease does not extend beyond a few bare patches. However, in some people, the hair loss is more extensive.

Alopecia totalis
A form of alopecia areata that leads to total hair loss from the scalp and face.

Alopecia universalis
A form of alopecia areata that leads to total hair loss on the scalp, face, and body.

Alpha hydroxy acid (AHA)
This is a type of chemical compound applied to the skin to provide a more youthful appearance.
Alpha hydroxy acids include glycolic, lactic, and fruit acids. Blended into lotions and chemical peel solutions, these ingredients break down the uppermost layer of skin cells, increasing cell turnover and lead to fuller, younger-looking skin.

Alpha lipoic acid
This is an antioxidant that can help to prevent premature aging of the skin, including the development of fine lines and wrinkles, when it is taken orally or used topically.

Anagen
This is the growing phase of the hair follicle. Each hair follicle goes through a growth phase (anagen) that last several years, before a resting phase (telogen) that last several months. Finally there is the declining phase (catagen).

Antioxidant
Antioxidants prevent free radicals from damaging cells. It is theorized by some that antioxidants may reduce the impact of sun-damage on skin, such as wrinkles and brown spots. Some antioxidants applied to the skin include idebenone (Prevage), coenzyme QlO, vitamins C and E, and botanicals like soy, green tea, malic acid, and pomegranate. Some suggest that antioxidants applied to the surface of the skin do not penetrate to sufficiently deep levels to have a significant impact on skin health.

Artefill
This filler is made from microspheres of polymethyl methacrylate (Lucite) suspended in bovine (cow) collagen. The collagen is absorbed by the body after two to four months, leaving behind tiny spherical beads that remain permanently in the skin.

Atopic Dermatitis
Atopic dermatitis, sometimes referred to as "eczema" is a chronic skin disorder that causes dry, itchy, and inflamed skin. The rash of Atopic dermatitis comes and goes in cycles. The worsening of atopic dermatitis ("flares") can be brought on by a variety of triggers.

Learn more about atopic dermatitis.

Atopy (atopic)
A genetic predisposition to the development of hypersensitivities, including allergies, and asthma.

Atrophy
A decrease in the volume of tissue. Atrophic skin is thin and may appear slightly sunken.

Autoimmune disease
A disease that occurs when the immune system mistakenly attacks the body's own tissues ("auto" means self). Examples include rheumatoid arthritis and systemic lupus erythematosus (SLE).

Return to Top

Last updated November 25, 2009

This information is for general educational uses only. It may not apply to you and your specific medical needs. This information should not be used in place of a visit, call, consultation with or the advice of your physician or health care professional. Communicate promptly with your physician or other health care professional with any health-related questions or concerns.

Be sure to follow specific instructions given to you by your physician or health care professional.

 

This website is certified by Health On the Net Foundation. Click to verify. This site complies with the HONcode standard for trustworthy health information:
verify here.
View Content Policy