Dermatofibromas are small red-to-brown bumps that result from an accumulation of collagen, which is a protein made by the cells (fibroblasts) that populate the soft tissue under the skin.
(See also Overview of Skin Growths.)
Dermatofibromas are common among adults and usually appear as single firm bumps, often on the thighs or legs, and particularly in women. The bumps are usually less than half an inch in diameter. Some people develop many dermatofibromas.
These harmless bumps are caused by a certain gene.
Dermatofibromas are harmless and usually do not cause any symptoms, except for occasional pain or itching.
Usually, dermatofibromas are not treated unless they become bothersome or enlarge. A doctor can surgically remove them if needed.