Scab A collection of dried body fluid and dead skin cells; a scab.

Scabies: Scabies is caused by a tiny mite that has infested humans for at least 2,500 years. It is often hard to detect, and causes a fiercely, itchy skin condition. Dermatologists estimate that more than 300 million cases of scabies occur worldwide every year. The condition can strike anyone of any race or age, regardless of personal hygiene. The good news is that with better detection methods and treatments, scabies does not need to cause more than temporary distress.

Scaling Abnormal shedding or accumulation of an upper layer of skin (the stratum corneum

Sebaceous glands: Glands in the skin that produce an oily substance called sebum--these glands are the sites of acne lesions. Sebaceous glands are attached to hair follicles and are found mostly on the face, neck, back and chest.

Sebum: The oily substance produced by sebaceous glands.

Scar: A scar is the fibrous tissue replacing normal tissues destroyed by injury or disease.

Sclerotherapy: A treatment for varicose veins and spider veins. A chemical solution injected into the enlarged vein causes it to collapse and form scar tissue.

Skin: The skin is the body's outer covering. It protects us against heat and light, injury, and infection. It regulates body temperature and stores water, fat, and vitamin D. Weighing about 6 pounds, the skin is the body's largest organ. It is made up of two main layers; the outer epidermis and the inner dermis.

Seborrheic keratoses:: Brown or black raised spots, or wart-like growths that appear to be stuck to the surface of the skin. They are harmless but unsightly..

Seborrheic eczema: yellowish, oily, scaly patches of skin on the scalp, face, and occasionally other parts of the body

Seborrheic dermatitis: Is a common inflammation of the upper layers of skin, characterized by loose, greasy or dry, white to yellowish scales , with or without associated reddened skin..Mainly affecting the scalp, face and trunk causing scaly, flaky, itchy, red skin. It is marked by small discolored patches or spots on the skin, often aggravated by cold weather conditions.

Shingles: Medical condition that develops when the varicella-zoster virus, the virus that causes chicken pox, is reactivated. The first sign is usually a rash that forms a band or patch of raised bumps. As shingles progresses, small blisters form. A person may experience mild to severe itching and pain. Other symptoms are fever, chills, headache, and upset stomach. Shingles only occurs in people who have had chicken pox.

Skin biopsy: Is most frequently done to diagnose a skin growth such as a mole, or a skin condition such as a rash. A skin biopsy can also be used to diagnose a cancer of the skin.

Skin tag: AIs a common, benign condition which consists of a bit of skin that projects from the surrounding skin and may appear attached to the skin.

Smallpox: Also known as variola, a highly contagious and frequently fatal viral disease characterized by a biphasic fever and a distinctive skin rash that left pock marks in its wake. Because of its high case-fatality rates and transmissibility, smallpox now represents a serious bioterrorist threat. The disease is caused by the variola virus. The incubation period is about 12 days (range: 7 to 17 days) following exposure. Initial symptoms include high fever, fatigue , and head and back aches. A characteristic rash, most prominent on the face, arms, and legs, follows in 2-3 days. The rash starts with flat red lesions that evolve at the same rate. Lesions become pus-filled and begin to crust early in the second week. Scabs develop and then separate and fall off after about 3-4 weeks.

Soft-tissue augmentation: A substance compatible with body tissues is injected under the skin to elevate irregularities such as wrinkles, pits and scars. Substances used for injection include collagen and self-donated body fat.

Spider veins: Small, superficial veins that enlarge and appear as a "sunburst" pattern of reddish and purplish veins.

Sporotrichosis: Is an infection of the skin caused by a fungus, Sporothrix schenckii. This infection-causing fungus is related more closely to the mold on stale bread or the yeast used to brew beer than to bacteria that usually cause infections. The mold is found on rose thorns, hay, sphagnum moss, twigs, and soil. Therefore, the infection is more common among gardeners who work with roses, moss, hay, and soil.

Stasis dermatitis: a skin irritation on the lower legs, generally related to circulatory problems

Staphylococcus: A group of bacteria that cause a multitude of diseases. Under a microscope, Staphylococcus bacteria are round and bunched together. They can cause illness directly by infection, or indirectly through products they make, such as the toxins responsible for food poisoning and toxic shock syndrome. The best known member of the Staphylococcus family is Staphylococcus aureus. Staphylococcus are the main culprit in hospital-acquired infections, and cause thousands of deaths every year.

Squamous cell carcinoma: A skin cancer that develops in the outer layers of the skin. It is one of the forms of skin cancer closely associated with aging and years of sun exposure. Squamous cell carcinoma is capable of spreading to other organs and should be treated as soon as it is detected.