What Is a Dermatofibroma?
A dermatofibroma is a common, benign (non-cancerous) skin growth made up of fibrous tissue. These small, firm bumps typically appear on the legs, arms, or upper back, and are more common in adults, especially women.
Dermatofibromas are not dangerous, but they can persist for years and may become irritated or itchy.
Key Characteristics
Appearance: Small, firm, raised bump—often brown, reddish-brown, or tan
Size: Usually less than 1 cm, but may grow slightly larger
Texture: Hard or rubbery; may feel like a "knot" under the skin
Color: May darken over time or vary slightly depending on skin tone
Location: Common on legs, arms, and shoulders
Sensation: Usually painless, May be itchy, tender, or sensitive to touch, Dimpling occurs when pinched (known as the "dimple sign")
What Causes It?
The exact cause of dermatofibromas is not always known, but they often develop in response to minor skin trauma or injury, such as:
Insect bites
Shaving cuts
Ingrown hairs
Other small injuries or inflammation
Dermatofibromas are not contagious, not cancerous, and do not become skin cancer.
When to See a Doctor?
Dermatofibromas are generally harmless and don’t require treatment. However, you should see a dermatologist if:
The bump is growing rapidly
It becomes painful, bleeds, or changes color
You're unsure whether it’s a dermatofibroma or another type of lesion
You’re concerned about cosmetic appearance or irritation from clothing
A dermatologist can usually diagnose a dermatofibroma through a physical exam, and may perform a biopsy if the diagnosis is unclear.
Treatment Options
Since dermatofibromas are benign, treatment is optional and usually based on cosmetic preference or discomfort.
Non-Surgical Options
Observation only: Most do not require any treatment
Cryotherapy (freezing): May flatten the bump but won’t remove it completely
Laser therapy: Can reduce pigmentation, but not always fully effective
Surgical Removal
Excision: Complete surgical removal under local anesthesia
Leaves a scar, which may be larger than the original bump
Best for cases with persistent discomfort or cosmetic concern
Dermatofibromas usually do not recur after full excision, but new ones may form elsewhere.
Living With It
Living with a dermatofibroma is generally low-maintenance:
Monitor for changes in size, shape, or color
Avoid picking or scratching the area
Use moisturizers to reduce any irritation or dryness
Talk to your dermatologist about removal if it's bothering you physically or aesthetically
While harmless, dermatofibromas can be an ongoing cosmetic concern—but they are not dangerous, and treatment is available if needed.
If you have further questions about Dermatofibromas or would like to schedule an appointment with a dermatologist please give us a call at 865-545-0900 or schedule online via book my appointment. If you have any questions, fill out our appointment request and we’ll reach out to you within a business day.
