Common warts are small, grainy skin growths that occur most often on your fingers or hands. Rough to the touch, common warts also often feature a pattern of tiny black dots, which are small, clotted blood vessels.
Common warts are caused by a virus and are transmitted by touch. It can take a wart as long as two to six months to develop after your skin has been exposed to the virus. Common warts are usually harmless and eventually disappear on their own. But many people choose to remove them because they find them bothersome or embarrassing.
1. Symptoms
Common warts usually occur on your fingers or hands and may be:
Small, fleshy, grainy bumps
Rough to the touch
Sprinkled with black pinpoints, which are small, clotted blood vessels
When to see a doctor
See your doctor for common warts if:
The growths are painful or change in appearance or color
You've tried treating the warts, but they persist, spread or recur
The growths are bothersome and interfere with activities
You aren't sure whether the growths are warts
You are an adult and numerous warts begin to appear, which may indicate the immune system is malfunctioning
2. Causes
Common warts are caused by the human papillomavirus (HPV). The virus is quite common and has more than 150 types, but only a few cause warts on your hands. Some strains of HPV are acquired through sexual contact. Most forms, however, are spread by casual skin contact or through shared objects, such as towels or washcloths. The virus usually spreads through breaks in your skin, such as a hangnail or a scrape. Biting your nails also can cause warts to spread on your fingertips and around your nails.
Each person's immune system responds to the HPV virus differently, so not everyone who comes in contact with HPV develops warts.
3. Risk factors
People at higher risk of developing common warts include:
Children and young adults, because their bodies may not have built up immunity to the virus
People with weakened immune systems, such as those with HIV/AIDS or people who've had organ transplants
4. Prevention
To reduce your risk of common warts:
Avoid direct contact with warts. This includes your own warts.
Don't pick at warts. Picking may spread the virus.
Don't use the same emery board, pumice stone or nail clipper on your warts as you use on your healthy skin and nails. Use a disposable emery board.
Don't bite your fingernails. Warts occur more often in skin that has been broken. Nibbling the skin around your fingernails opens the door for the virus.
Groom with care. And avoid brushing, clipping or shaving areas that have warts. If you must shave, use an electric razor.
5. Diagnosis
In most cases, your doctor can diagnose a common wart with one or more of these techniques:
Examining the wart
Scraping off the top layer of the wart to check for signs of dark, pinpoint dots — clotted blood vessels — which are common with warts
Removing a small section of the wart (shave biopsy) and sending it to a laboratory for analysis to rule out other types of skin growths.