What is a dermatofibroma?
A dermatofibroma is a common overgrowth of the fibrous tissue situated in the dermis (the deeper of the two main layers of the skin). It is benign (harmless) and will not turn into cancer. While dermatofibromas are harmless, they can be similar in appearance to others concerning skin tumors. It is, therefore, essential to see a health professional for a diagnosis.
What causes a dermatofibroma to appear?
The exact cause of dermatofibroma is not clear. However, these fibromas often seem to appear after a minor injury such as a thorn prick or an insect bite. Specific patient groups can be more prone to developing dermatofibromas.
What are the symptoms of a dermatofibroma?
Usually, there are no symptoms, but some people may be concerned about their appearance. Occasionally dermatofibromas can itch or become painful when touched or knocked. If they are on the legs, shaving the skin over them can cause bleeding.
How do dermatofibromas look like?
- A firm bump that feels like a small rubbery button lying just under the surface of the skin, seldom larger than 1 cm in diameter.
- They can vary in color from purple to pink and can sometimes appear brown or grey.
- A dimple may appear over a dermatofibroma when pinched.
- They can appear anywhere but are most common on the lower legs of young to middle-aged adults, and on the upper arms in females.
Will I get more than one dermatofibroma?
Most people with a dermatofibroma will have only one.
How is dermatofibroma diagnosed?
A doctor can usually identify a dermatofibroma easily by its appearance. However, if there is doubt about the diagnosis or possibility of skin cancer, then get it removed by a local anesthetic. Then it can be looked at under a microscope.
What are the treatment options for dermatofibroma?
Dermatofibromas sometimes disappear without any treatment, although in many cases, they can last indefinitely. Because they are harmless, treatment is not usually necessary other than an accurate diagnosis and reassurance.
Treatment options include
- Intralesional steroid injections (steroid injections into the lesion), which can cause the dermatofibroma to flatten slightly
- Cryotherapy (freezing with liquid nitrogen), but this will leave a scar, and the lesion may recur.
- Some lasers, including carbon dioxide lasers (which work to flatten the lesion) and pulsed dye lasers (which target the blood supply to the lesion), have shown promising results but may also scar.
- Excision (surgical removal) under local anesthetic can be done. This option will always leave a scar, which may be as troublesome as the original lesion.