Diseases & conditions

acne

Inflammatory disorder of the sebaceous glands that produces pimples on the skin.

albinism

An inherited condition that prevents the normal production of melanin, resulting in extremely pale skin and white hair.

alopecia

Hair loss that results from genetics, normal aging, illness, or drugs used to treat certain diseases.

basal cell carcinoma

A commonly slow-growing, malignant tumor of the basal cell layer of the epidermis that typically does not metastasize.

cicatrix

A scar left by a healed wound.

cyanosis

The appearance of a blue or purple discoloration of the skin or mucous membranes due to insufficient blood oxygen or poor circulation.

cyst

A closed, thick-walled sac or pouch containing fluid or semisolid material that develops in a cavity or other structure of the body.

ecchymosis

Black-and-blue or purplish bruise caused by ruptured blood vessels beneath the skin.

eczema

Acute or chronic inflammatory skin disease characterized by erythema, itchiness, and edema (swelling).

first-degree burn

A skin burn characterized by superficial epidermal lesions.

fissure

A groove or crack; also known as a sore.

gangrene

Necrosis, or death, of tissue due to loss of blood supply, followed by bacterial infection.

impetigo

Bacterial infection of the skin characterized by vesicles (small, fluid-filled sacs), pustules (small, pus-filled blisters), and crusted-over lesions.

Kaposi’s sarcoma

Malignant cancer that causes erythematous (red) or purplish patches in the lining of the mouth, nose, and throat or in other organs and tissues; a disease often seen in patients with AIDS.

keloid

An abnormally raised, thickened scar.

macule

A small, flat, discolored (brownish or red) lesion on the skin; also known as a freckle.

malignant melanoma

A cancerous growth composed of melanocytes that begins as an irregularly shaped macule and then changes color and texture; classified as level I, II, III, or IV, depending on level of penetration.

nevus

A highly pigmented lesion of the skin that is flat or raised; also known as a mole.

nodule

A solid skin elevation larger than 1 centimeter in diameter; may develop in the epidermis, dermis, or subcutaneous layer.

papule

A solid skin elevation with distinct borders and a diameter of less than 1 centimeter; also known as a pimple.

petechia

Round, pinpoint spots on the skin caused by intradermal hemorrhage.

polyp

A small, mushroom-like growth, typically benign, that extends from the surface of a mucous membrane.

psoriasis

A chronic disease marked by itchy, erythematous skin with silvery patches.

purpura

A purple or brownish-red rash in which blood leaks from vessels into the skin or mucous membranes.

pustule

A small, infected skin elevation that contains pus; also known as an abscess.

scabies

A contagious, parasitic infection of the skin with intense pruritus (itching).

scleroderma

A chronic, progressive disease of the skin marked by hardening and shrinking of connective tissue, which causes edema or pain in the muscles or joints.

second-degree burn

A skin burn characterized by epidermal and dermal lesions, erythema, blisters, and hyperesthesia.

squamous cell carcinoma

Malignant tumor of the squamous epithelial cells of the epidermis; may grow in other organs lined with epithelial cells.

systemic lupus erythematosus (SLE)

A chronic, inflammatory disease of collagen in the skin, joints, and internal organs. SLE is an autoimmune disease.

third-degree burn

A skin burn in which the epidermis and dermis are destroyed.

tinea

A skin infection caused by a fungus.

ulcer

An open sore or an erosion of the skin or lining of a mucous membrane.

urticaria

Condition characterized by hives with localized swelling and itching.

varicose veins

Veins that have a twisting appearance due to loss of elasticity.

vesicle

A small, raised skin lesion filled with clear fluid; also known as a blister.

vitiligo

Loss of pigment in one or more areas of the skin, creating the appearance of milky-white patches.

wart

A small, hard, benign skin growth caused by a virus (usually a papillomavirus).

wheal

A smooth, slightly swollen area that is redder or paler than the surrounding skin; a characteristic of hives.