keratin
horny, or cornified, layer composed of protein. It is contained in the hair, skin, and nails
sudoriferous (sweat) glands
tiny, coiled, tublular structures that emerge through pores on the skin's surface and secrete sweat
sebaceous glands
secrete sebum (oil) into the hair follicles where the hair shafts pass through the dermis
nails
originate in the epidermis. The white area at the base of the nail is called the lunula, or moon
actinic keratosis
a precancerous skin condition of horny tissue formation that results from excessive exposure to sunlight. It may evolve into a squamous cell carcinoma.
albinism
congenital hereditary condition characterized by partial or total lack of pigment in the skin, hair, and eyes
basal cell carcinoma (BBC)
epithelial tumor arising from the epidermis. It seldom metastasizes but invades local tissue. Common in individuals who have had excessive sun exposure.
candidiasis
an infection of the skin, mouth (also called thrush), or vagina caused by the yeast-type fungus Candida albicans
cellulitis
inflammation of the skin and subcutaneous tissue caused by infection, leading to redness, swelling, and fever
contusion
injury with no break in the skin, characterized by pain, swelling, and discoloration (also called a bruise)
eczema
noninfectious, inflammatory skin disease characterized by redness, blisters, scabs, and itching
furuncle
painful skin node caused by staphylococcal bacteria in a hair follicle (also called a boil)
gangrene
death of tissue caused by loss of blood supply followed by bacterial invasion (a form of necrosis)
impetigo
superficial skin infection caused by pustules and caused by either staphylococci or streptococci
infection
the invasion of pathogens in body tissue. Can be caused by bacteria, fungus, parasite, or virus
Kaposi sarcoma
a cancerous condition starting as purple or brown papules on the lower extremities that spreads through the skin to the lymph nodes and internal organs. Frequently seen with AIDS
lesion
any visible change in tissue resulting from injury or disease. It is a broad term that includes sores, wounds, ulcers, and tumors
MRSA infection
invasion of body tissue by methicillin-resistant Staphylococcus aureus, a strain of common bacteria that has developed resistance to penicillin and other antibiotics. It can produce skin and soft tissue infections and sometimes bloodstream infections and pneumonia, which can be fatal if not treated
rosacea
chronic disorder of the skin that produces erythema, papules, pustules, and broken blood vessels, usually occurring on the central area of the face in people older than 30 years (also called acne rosacea)
scabies
skin infection caused by the itch mite, characterized by papule eruptions also accompanied by severe itching
scleroderma
a disease characterized by chronic hardening (induration) of the connective tissue of the skin and other body organs
squamous cell carcinoma (SqCCA)
a malignant growth that develops from scalelike epithelial tissue. Unlike basal cell carcinoma, there is a significant potential for metastasis. The most frequent cause is chronic exposure to sunlight
systemic lupus erthematosus (SLE)
a chronic inflammatory disease involving the skin joints, kidneys, and nervous system. This autoimmune disease is characterized by periods of remission and exacerbations. It also may affect other organs
tinea
fungal infection of the skin. The fungi may infect keratin of the skin, hair, and nails. (also known as ringworm or athlete's foot)
urticaria
an itching eruption composed of wheals of varying size and shape, which usually resolves in a short period of time. Often idiopathic but sometimes associated with infections and with allergic reactions to food, medicine, or other agents. Other causes include internal disease, physical stimuli, and genetic disorders (also called hives)
vitiligo
white patches on the skin caused by the destruction of melanocytes associated with autoimmune disorders
cauterization
destruction of tissue with a hot or cold instrument, electric current, or caustic substance (also called cautery)
incision and drainage
surgical cut made to allow the free flow or withdrawal of fluids from lesion, wound, or cavity
laser surgery
procedure using an instrument that emits a high-powered beam of light used to cut, burn, vaporize, or destroy tissue
bacteria (s. bacterium)
single-celled microorganisms that reproduce by cell division and may cause infection by invading body tissue
cytomegalovirus
a herpes-type virus that usually causes disease when the immune system is compromised
ecchymosis (pl. ecchymoses)
escape of blood into the skin (or mucous membrane), causing a small, flat, purple, or blue discoloration, as may occur when blood is withdrawn by a needle and syringe from an arm vein
fungus (pl. fungi)
organism that feeds by absorbing organic molecules from its surroundings and may cause infection by invading body tissue; single-celled fungi (yeast) reproduce by budding; multicelled fungi (mold) reproduce by spore formation
leukoplakia
condition characterized by white spots or patches on mucous membrane which may be precancerous
nevus
circumscribed malformation of the skin, usually brown, black, or flesh colored. A congenital nevus is present at birth and is referred to as a birthmark (also called a mole)
pressure ulcer (decub)
erosion of the skin caused by prolonged pressure, often occurring in bedridden patients (also called decubitus ulcer or bed sore)
purpura
small hemorrhages in the skin (or mucous membrane), giving a purple-red discoloration; associated with blood disorders or vascular abnormalities
virus
minute microorganism, much smaller than bacterium, characterized by a lack of independent metabolism and the ability to replicate only within living host cells; may cause infection by invading body tissue
wheal
transitory, itchy elevation of the skin with a white center and a red surrounding area; a wheal is an individual urticaria (hive) lesion