Warts are a common viral infection that can grow in the skin around or under your nails. When warts appear under your fingernails or toenails, they are referred to as subungual warts. Unlike warts found elsewhere on your body, subungual warts may be quite painful and are hard to cure.
Warts are caused by the human papillomavirus, which resides in the bottom layer of the skin's epidermis. They occur most commonly in children and young adults. According to the American Academy of Dermatology, people who bite their nails or pick at hangnails appear to be especially vulnerable to subungual warts because they are breaking the surface of their skin, which allows the virus to penetrate into the nailbed. Manicures, if performed aggressively, or minor injuries can also increase your vulnerability. People with compromised immune systems, such as those with AIDS or lymphoma, and people on chemotherapy also are more susceptible to warts.
Nails may become discoloured. Because subungual warts grow under your nail, pressure can build up in the affected finger or toe, which can become very painful. If not treated, subungual warts can distort nail growth and cause the nail to lift away or detach from the skin.
Warts may resolve spontaneously, but some linger for years. According to an article posted on the American Family Physicians website, both prescription and over-the-counter preparations that contain salicylic acid may present an effective treatment option for subungual warts. Soaking the affected area in warm water before applying salicylic acid may allow the medication to penetrate deeper into the wart. To manage resistant warts, the article suggested topical use of Retin-A or Efudex, alone or in combination. To avoid irritation, they should be applied at different times of the day. Please note that you will require a prescription from your doctor for these preparations and that neither is indicated to treat subungual warts.
Your Doctor Can Help
A physician may need to remove part of your nail to better access the wart. Once the wart is more accessible, a physician may try the medical therapies described previously or cryotherapy, a procedure in which liquid nitrogen is applied to the wart to freeze it, killing the affected cells. A physician may also opt to try carbon dioxide (CO2) laser treatment to vaporise the wart. CO2 therapy has been shown to be more effective than cryotherapy.
Some people say that duct tape is an effective treatment for subungual warts. They recommend that you wrap the duct tape around the affected nail two times, and leave it in place for six to seven days. If the wart persists, you can try a thicker roll of duct tape for another six days. Herbal remedies are also marketed to remove warts. The efficacy and safety of these treatments has not been assessed by the U.S. Food and Drug Administration.