Definition
Skin conditions with fat beneath the surface of the skin.

Alternative Names
Skin growths - fatty

Causes, incidence, and risk factors

Xanthomas are common skin disorders, particularly among older adults and persons with elevated blood lipids (fat levels).

Xanthomas are deposits of fatty materials under the surface of the skin ranging in size from very small to more than 3 inches in diameter. They may be a symptom of underlying metabolic disorders that are associated with an increase in blood lipids, including diabetes, primary biliary cirrhosis, some types of cancer, and inherited metabolic disorders including familial hypercholesterolemia (inherited tendency to high cholesterol levels). They can appear anywhere on the body, but commonly appear on the elbows, joints, tendons, knees, hands, feet, or buttocks.

Xanthelasma palpebra is a common type of xanthoma that appears on the eyelids.

Prevention
Control of blood lipids, including triglycerides and cholesterol levels, may help to reduce development of xanthelasmas and xanthomas. Control of underlying disorders will help reduce development.

Symptoms

skin lesion or bumps under the skin (nodules)
with a flat surface
soft to the touch
yellow color
sharply defined margins (sharp, distinct borders)

Signs and tests
The diagnosis is primarily on how the skin growth looks, especially if there is a history of an underlying disorder. A biopsy of the growth will show a fatty deposit.