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Descriptions of Skin Marks, Growths, and Color Changes


Julia Benedetti

, MD, Harvard Medical School

Reviewed/Revised Jan 2024
Topic Resources

Doctors use specific terms to describe various types of marks and growths on the skin. Some skin disorders and infections can cause color changes in the skin.

Types of Skin Marks and Growths

Atrophy is thinning of the skin that can sometimes result in a depression and often has a dry and wrinkled "cigarette paper" appearance.

Bullae are fluid-filled blisters that are greater than 10 millimeters (0.4 inch) in diameter (larger than vesicles).

Crusts (scabs) are dried blood, pus, or skin fluids on the surface of the skin. A crust can form wherever the skin has been damaged.

Cysts are thin-walled cavities filled with fluid or semi-liquid material. They often look and feel like a lump (nodule) in the skin.

Erosions are open areas of skin that result from loss of part or all of the top layers (epidermis Epidermis The skin is the body’s largest organ. It serves many important functions, including Protecting the body against trauma Regulating body temperature Maintaining water and electrolyte balance Sensing... read more Epidermis ) of the skin. Erosions occur when infection, pressure, irritation, or temperature has damaged the skin. They typically heal without scarring.

Excoriations are erosions caused by scratching, rubbing, or picking at the skin. Often, excoriations are covered with a crust.

Lesion is a general term for any abnormal mark or growth on the skin.

Lichenification is thickened skin that has accentuated skinfolds or creases that appear as deep grooves and wrinkles. Lichenification is caused by repeated scratching or rubbing.

Macules are flat, discolored spots of any shape less than 10 millimeters (0.4 inch) in diameter. Freckles, flat moles, port-wine stains, and many rashes are macular.

Nodules are solid raised areas that are usually round. They are deeper and easier to feel than papules. A nodule sometimes appears to form below the surface of the skin and press upward.

Patches are larger flat spots (greater than 10 millimeters).

Plaques are flat or raised areas or groups of small bumps (papules) typically more than 10 millimeters (0.4 inch) in diameter.

Pustules are fluid-filled spots (vesicles) containing pus.

Telangiectases are dilated blood vessels near the surface of the skin that often have a twisted appearance and that whiten (blanch) when pressure is applied.

Wheals (hives, urticaria) are elevated, itchy areas that are caused by swelling in the skin. In people who have light skin, hives are usually red. In people who have dark skin, hives may look closer to the color of surrounding skin. Wheals appear relatively suddenly and then almost always disappear within 24 hours. Wheals are common allergic reactions to drugs or medications, insect bites, or something that touches the skin. The presence of multiple wheals is called hives Hives Hives are red, itchy, slightly elevated swellings. The swelling is caused by the release of chemicals (such as histamine) from mast cells in the skin, which cause fluid to leak out of small... read more Hives or urticaria.

Examples of Skin Marks, Growths, and Color Changes in the Skin

Color Changes in the Skin

Although certain color changes are typical, the natural color of a person's skin can change the appearance of these colors.

Red skin (erythema) can result from many different disorders that cause inflammation or are caused by infection. Tumors on the skin are often pink or red, and disorders affecting blood vessels near the skin surface, such as port-wine stains Port-Wine Stains Port-wine stains are flat pink, red, or purplish discolorations present at birth due to malformed blood vessels. (See also Overview of Skin Growths and Overview of Growths and Malformations... read more Port-Wine Stains , may appear red. In people who have dark skin, the same conditions that cause redness can be more subtle (with possibly less contrast with surrounding skin) and harder to recognize.

Orange skin is most often the result of hypercarotenemia. Hypercarotenemia is a condition that is the result of too much of the pigment carotene in the blood. People who overeat foods rich in beta-carotene, such as carrots, may develop hypercarotenemia. In people who have dark skin, the orange may be more noticeable on the palms and soles.

Shades of blue, silver, and gray can occur when medications or metals, including minocycline, amiodarone, and silver (argyria), are deposited in the skin. Skin that has a blocked or poor supply may appear purple to gray in color. Some birthmarks and moles Moles Moles are small, usually dark, skin growths that develop from pigment-producing cells in the skin (melanocytes). Most people have some moles, but the tendency to develop atypical moles is sometimes... read more Moles (nevi) that are deep in the skin may appear blue.

Black skin lesions may contain specialized cells that produce the brown pigment melanin (melanocytes). Examples of these types of lesions include moles (nevi) and melanoma Melanoma Melanoma is a skin cancer that begins in the pigment-producing cells of the skin (melanocytes). Melanomas can begin on normal skin or in existing moles. They may be irregular, flat or raised... read more Melanoma . Thick, black, crusty scabs (called eschars) are collections of dead skin and can be caused by death of tissue (infarction).

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