Common Warts
Rough, harmless skin growths caused by a virus
Quick Facts
- Type: Viral skin growth
- Cause: Human papillomavirus (HPV)
- Common areas: Hands, fingers, around nails
- Outlook: Often harmless, may clear on their own
Overview
Common warts are small, rough, raised growths on the skin caused by infection with the human papillomavirus (HPV). They most often appear on the hands, fingers, and around the nails, though they can develop elsewhere. The virus enters through tiny breaks in the skin and causes the surface cells to grow more quickly, forming the characteristic bump.
Common warts are harmless and not cancerous, but they can be unsightly, occasionally uncomfortable, and they spread easily through contact. Many warts eventually disappear on their own as the immune system clears the virus, though this can take months to years, which is why people often choose to treat them.
Symptoms
Common warts have several recognizable features:
- Small, firm, rounded bumps with a rough, grainy surface
- A color similar to the surrounding skin, or slightly grayish, brown, or pink
- Tiny black dots within the wart, which are small clotted blood vessels
- A single wart or clusters of several
- Mild tenderness, especially if located on a finger or near a nail
They are usually painless, although warts on the hands can become sore if they are knocked or catch on things. Warts that bleed easily, change color, or look unusual should be checked by a doctor.
Causes
Common warts are caused by certain strains of HPV. The virus is widespread and spreads through:
- Direct skin contact: Touching a wart on yourself or another person.
- Shared surfaces and objects: Towels, razors, or other items used by someone with warts.
- Self-spread: Scratching, picking, or biting warts can move the virus to other parts of the body.
The virus enters through small cuts, scrapes, or areas of broken skin. It may take weeks to months after exposure before a wart becomes visible.
Risk Factors
- Being a child or young adult, as warts are most common in these age groups
- Having cuts, scrapes, or other breaks in the skin
- Biting nails or picking at the skin around the nails
- A weakened immune system
- Frequent skin contact in shared environments
Diagnosis
Doctors can almost always diagnose common warts simply by looking at them:
- Visual examination: The rough surface and tiny black dots are usually enough to confirm a wart.
- Paring the surface: Gently scraping the top can reveal the small clotted blood vessels typical of warts.
- Biopsy: Rarely needed, but a small sample may be taken if the growth looks unusual or does not respond to treatment.
Treatment
Many common warts clear up on their own, but treatment can speed this up, especially if they are bothersome. Options include:
- Salicylic acid: Over-the-counter gels, liquids, or patches that gradually remove the wart with repeated use.
- Cryotherapy: Freezing the wart with liquid nitrogen, usually in a clinic, sometimes over several sessions.
- Other in-office treatments: Such as minor procedures, laser treatment, or prescription medicines for stubborn warts.
Treatment often takes several weeks and warts can return, so persistence is important. Avoid trying to cut warts off at home, which can cause infection and scarring.
Prevention
- Avoid touching warts, on yourself or others
- Do not share towels, razors, or nail tools
- Keep skin clean and cover cuts and scrapes
- Avoid biting nails or picking at warts, which spreads the virus
- Wash your hands after touching a wart
When to See a Doctor
See a doctor if a wart:
- Is painful, bleeds, or changes in color or appearance
- Spreads, multiplies, or does not respond to over-the-counter treatment
- Appears on the face or another sensitive area
- Develops in someone with diabetes or a weakened immune system
Any new or changing skin growth that you are unsure about should be evaluated, since a doctor can confirm it is a harmless wart and rule out other skin conditions.
Frequently Asked Questions
Are common warts contagious?
Yes. Common warts are caused by a virus and spread through direct skin contact or by sharing items such as towels and razors. Scratching or picking at a wart can also spread it to other parts of your own body.
Will common warts go away on their own?
Many common warts eventually clear as the immune system fights off the virus, but this can take months to a couple of years. Treatment can speed the process, which is helpful when warts are painful, spreading, or bothersome.
What is the best way to treat a common wart at home?
Over-the-counter salicylic acid products, used consistently over several weeks, are a common first step. Soaking the wart and gently filing the surface before applying can help, but avoid cutting warts off yourself, which risks infection and scarring.
Why do warts have little black dots?
The tiny black dots inside a wart are small clotted blood vessels, not 'seeds' or roots. They are a normal feature of warts and one of the clues doctors use to identify them.
When should I see a doctor about a wart?
See a doctor if a wart is painful, bleeds, changes color or shape, spreads, appears on the face, or does not respond to over-the-counter treatment. People with diabetes or a weakened immune system should have warts checked rather than self-treating.
References
- American Academy of Dermatology. Warts: Overview.
- MedlinePlus, U.S. National Library of Medicine. Warts.
- Centers for Disease Control and Prevention (CDC). Human Papillomavirus (HPV).
- Mayo Clinic. Common warts — Symptoms and causes.