Dermatology Glossary

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acne - a chronic disorder of the hair follicles and sebaceous glands. Acne is characterized by pimple outbreaks, cysts, infected abscesses, and sometimes scarring.

albinism - a rare, inherited disorder characterized by a total lack of melanin (skin pigment) in the skin.

angioma - a benign tumor in the skin, made up of blood or lymph vessels.

atrophic skin - skin that is thin and wrinkled.

basal cells - these cells are found in the outer layer of skin. Basal cells are responsible for producing the squamous cells in the skin.

basal cell carcinoma - the most common form of skin cancer, characterized by small, shiny, raised bumps on the skin that may bleed.

birth marks - areas of discolored and/or raised skin that are present at birth or shortly afterward.

bed sores - ulcers that occur on areas of the skin that are under pressure from lying in bed, sitting in wheelchairs, wearing a cast, or being immobile for a long period of time.

biopsy - the procedure of removing tissue for examination under a microscope.

blister- a fluid-filled bump.

boil - tender, swollen areas that form around hair follicles.

candidiasis (Also called yeast infection.) - a skin infection caused by yeast that can occur in the skin folds, the navel, vagina, penis, mouth, and nail beds.

carbuncles - clusters of boils on the skin.

cavernous hemangioma - a raised, red or purple mark in the skin, made up of enlarged blood vessels.

cellulitis - a bacterial infection of the skin that is characterized by swelling and tenderness.

cold sore - small blisters around and in the mouth caused by the herpes simplex virus.

collagen - a protein produced by skin cells that provide strength and resilience to the skin.

creeping eruption - a skin infection caused by hookworms that is characterized by severe itching.

crust (Also called scab.) - a formation of dried blood, pus, or other skin fluid over a break in the skin.

cryosurgery - a surgery technique that uses liquid nitrogen to freeze the skin.

cyst - a deep lesion that is filled with pus.

dermatitis- a number of skin conditions that inflame the skin.

dermatofibroma - small, red or brown bumps in the skin.

dermis - the middle layer of skin, which is made up of blood vessels, lymph vessels, hair follicles, and sweat glands.

dermoid cyst - a benign tumor made up of hairs, sweat glands, and sebaceous glands.

epidermis - the outer layer of skin, which is made up of the horny layer, squamous cells and basal cells.

erysipelas - a skin infection that usually affects the arms, legs, or face, characterized by shiny, red areas, small blisters, and swollen lymph nodes.

erythema multiforme - a skin condition characterized by symmetrically positioned, red, raised skin areas all over the body.

erythema nodosum - a skin condition, characterized by red bumps that usually appear on the shins.

erythrasma - a skin infection of the top layer of skin characterized by irregular pink patches that turn to brown scales.

excoriation - a hollowed-out or linear area of the skin covered by a crust.

folliculitis - an inflammation of the hair follicles due to an infection.

freckles - darkened, flat spots that typically appear only on sun-exposed areas of skin.

granuloma annulare - a chronic skin condition characterized by small, raised bumps that form a ring with a normal or sunken center.

herpes zoster (Also called shingles.) - a common viral infection of the nerves, characterized by a painful skin rash of small blisters anywhere on the body.

hives (Also called wheals.) - a pink swelling of the skin.

impetigo - a skin infection characterized by pus-filled blisters.

keloids - smooth, pink, raised, fibrous growths on the skin that form over healed wounds.

keratinocytes (Also called squamous cells.) - these are the primary cell types found in the epidermis -- the outer layer of skin.

keratoacanthomas - round, flesh-colored growths with craters that contain a pasty material.

keratosis pilaris - a common skin condition characterized by small, pointed pimples.

lice - tiny insects that can infest the skin; characterized by intense itching.

lichenification - skin that has thickened.

lipomas- round or oval lumps under the skin caused by fatty deposits.

lymphangioma - a raised, yellow-tan or red mark in the skin, made up of enlarged lymphatic vessels.

macular stains (Also called angel's kisses or stork bites.) - faint, red marks that appear in the skin at birth. Angel's kisses are marks on the forehead and eyelids. Stork bites are marks on the back of the neck.

macule - the smaller version of a patch -- a flat discolored spot.

malignant melanoma - a rare, but deadly, skin cancer that begins as a mole that turns cancerous.

melanocytes - cells present in the epidermis that produce melanin (skin pigment).

melasma - dark, brown symmetrical patches of pigment on the face.

moles - small skin marks caused by pigment-producing cells in the skin.

Mongolian spots - Bluish-black marks on the lower back and buttocks; affects mainly African-American or Asian children.

nodule (Also called papule.) - a solid, raised bump.

paranychia- a skin infection around a finger or toenail.

patch -a flat, discolored spot.

pityriasis rosea - a common skin condition characterized by scaly, pink, and inflamed skin.

port-wine stains (Also called nevi flammeus.) - permanent flat, pink, red, or purple marks on the skin.

prickly heat - a rash caused by trapped sweat under the skin.

psoriasis - a chronic skin condition characterized by inflamed, red, raised areas that develop silvery scales.

pustule (Also called pimple.) - inflamed lesions that look like pink bumps.

pyogenic granuloma -red, brown, or bluish-black raised marks caused by excessive growth of capillaries.

raised bumps - bumps that stick out above the skin surface.

ringworm -a fungal skin infection characterized by ring-shaped, red, scaly, or blistery patches.

rosacea -a common skin condition characterized by redness, pimples, and broken blood vessels.

salicylic acid - a keratolytic drug (a drug that removes the outer layer of skin) used to treat various skin conditions.

sarcoidosis - an inflammation of the lymph nodes and other organs.

scabies - an infestation of mites in the skin characterized by small pimples that itch.

scales- dead skin cells that look like flakes or dry skin.

scar - fibrous tissue that has formed after a skin injury.

sebaceous glands - glands in the skin that secrete oil to the surface of the skin.

seborrheic keratosis - flesh-colored, brown, or black wart-like spots.

skin tags - soft, small, flesh-colored skin flaps on the neck, armpits, or groin.

spider angioma - a bright red mark with a distinct dark spot in the skin.

squamous cells- see keratinocytes.

squamous cell carcinoma - a form of skin cancer that affects about 20 percent of patients with skin cancer. This highly treatable cancer is characterized by red, scaly skin that becomes an open sore.

strawberry mark (Also called capillary hemangioma.) - a raised, strawberry red mark in the skin.

subcutis - the deepest layer of skin; consists of collagen and fat cells.

tinea versicolor - a common fungal skin infection characterized by white or light brown patches on the skin.

toxic epidermal necrolysis - a life-threatening skin disorder characterized by blistering and peeling of the top layer of skin.

tretinoin - a drug which is chemically related to vitamin A; used to treat acne and other scaly skin disorders.

urushiol - resin in poison ivy plants that causes a skin reaction.

vitiligo - smooth, white patches in the skin caused by the loss of pigment-producing cells.

wart - a noncancerous skin growth caused by a virus.

Reprinted with permission of the University of Maryland Medicine (www.umm.edu).