Dermatology Library

E

Ectodermal dysplasia:

The ectodermal dysplasia (ED) syndromes are a group of about 150 heritable disorders that affect the ectoderm, the outer layer of tissue in a developing baby. ED syndromes affect both males and females of all races and ethnic groups. The ectoderm contributes to the formation of many parts of the body, including the skin, sweat glands, hair, teeth, and nails. During embryonic development, these and/or other parts of the baby’s body, including the lens of the eye, parts of the inner ear, the fingers and toes, or nerves, among others, may fail to develop normally. When a child has at least two types of abnormal ectodermal features-for example, malformed teeth and extremely sparse hair-the child is identified as being affected by an ED "syndrome." Each of the roughly 150 ED syndromes represents a different combination of abnormalities. Physical symptoms can range from mild to extremely severe. Very few types of ED involve learning difficulties.

Eczema:

The terms eczema or dermatitis are used to describe certain kinds of inflamed skin conditions including allergic contact dermatitis and nummular dermatitis. Eczema can be red, blistering, oozing, scaly, brownish, or thickened skin and usually itches. A special type is called atopic dermatitis or atopic eczema.

Emollient:

A topical application, such as a cream, lotion or ointment that can make the skin soft or supple.

Epidermis:

The outermost layer of skin. The epidermis has several active zones of skin cells, including cells that participate in immune reactions. Many eczematous skin conditions are initiated in the epidermis.

Ethnic Skin:

Most skin ailments occur in all skin types, regardless of the pigment of the skin. However, certain skin problems are more common among African-Americans and others with darker complexions. New York and Philadelphia dermatologist Susan C. Taylor, M.D., author of Brown Skin: Dr. Susan Taylor's Prescription for Flawless Skin, Hair, and Nails, commented on some of the more prevalent conditions she sees in her practice.

Dry or "Ashy Skin"

Dry skin is a problem for individuals of all skin colors, but may be very distressing to persons with brown or black skin. It's uncomfortable in all populations, but it is easily noticed in persons with brown or black skin because of its grayish, "ashy" appearance. Using moisturizers regularly can help tremendously. However, some of these products may worsen acne. All patients with acne should select "non-comedogenic" (meaning won't plug pores or cause acne) moisturizers. If the problem persists, see a dermatologist. Dry skin can also affect the scalp. Pomades that make the hair more manageable can decrease scalp dryness, but may aggravate seborrhea (dandruff). If pomade spreads to the forehead it can block pores, causing pimples called pomade acne. If this occurs, stop using the pomade or apply it only to the hair. Pomade can also contribute to an inflammation of the scalp called folliculitis. Folliculitis produces pus, bumps, and redness around the hair. It can also cause hair loss or can spread infection. If this occurs, discontinue using the pomade and see a dermatologist.

Variations in Skin Color

Skin color is determined by cells called melanocytes. All races have the same number of these cells. The melanocytes produce the pigment called melanin, which is contained in structures called melanosomes. Black skin has larger melanosomes and the melanosomes contain more of the pigment melanin than those found in white skin. Because of the protective effect of melanin, African-Americans are better protected against skin cancer and premature wrinkling from sun exposure. Post inflammatory hyperpigmentation is quite common in dark skinned individuals, even after minor trauma. An area of the skin may darken after an injury such as a cut or a scrape, or after certain skin disorders such as acne. Often black patients will request treatment for pigmentation secondary to acne. Treatment of acne will usually prevent development of new dark spots, and old dark spots will resolve with time. To avoid or reduce post inflammatory hyperpigmentation, avoid picking, harsh scrubbing, and abrasive treatments. Darkened areas of skin may take many months or years to fade, although topical (surface) bleaching agents may help. Dr. Taylor added, "Hyperpigmentation - or dark discoloration of the skin - is a major problem in individuals of African descent. If the pigmentation is in the upper layers of the skin (the epidermis), topical hydroquinone products are often helpful (as a single ingredient or in combination with other ingredients). Additionally, chemical peels (using alpha and beta hydroxyl acids) and microdermabrasion can be helpful."

Vitiligo

Vitiligo is a common condition where pigment cells are destroyed and irregular white patches on the skin appear. Many dermatologists think that the cause of this common disorder is an autoimmune process, where the cells of the body attack the pigment producing cells.

The extent of color loss differs with each person and there is no way to predict how much pigment a person will lose. Some people lose pigment over their entire bodies. Some patients with vitiligo do not regain skin color, however some cases of vitiligo do repigment. See your dermatologist as soon as possible, as the extent of the disease will determine the appropriate treatment. Several methods are used to treat vitiligo, but none have been perfected. Topical medications, including corticosteroids and new non-steroid anti-inflammatory preparations are commonly used. Another common method is PUVA therapy, combining phototherapy (light treatments) and medication. Laser treatment has also proved effective in re-pigmenting darker skin without risks of radiating the entire skin surface involved in PUVA therapy (see related story on laser therapy on page XXX). In cases where vitiligo affects most of the body, it is sometimes best to destroy the remaining normal pigment. A dermatologist can determine what treatment is best based on the extent of the disease.

Pityriasis Alba

People with pityriasis alba have round, light patches of the skin ("fade spots") covered with fine scales. It is most common in children. The patches can occur on any part of the body, but are most noticeable on the face and upper arms. The light patches are the result of mild eczema, and the loss of color is only temporary. This condition can be treated by a dermatologist.

Dermatosis Papulosa Nigra

Also called flesh moles, dermatosis papulosa nigra occurs almost exclusively in African- Americans, Native Americans and Hispanics and most frequently in women. These brown or black raised dark spots usually appear on the cheeks. They resemble moles or flat warts. They are not cancerous, but some patients have them removed for cosmetic reasons.

Excessive pigmentation:

See: Ethnic Skin

Exfoliation:

Peeling and sloughing off of the skin's tissue cells.