What are Warts? Warts are benign skin growths caused by the human papilloma virus. The virus,
which is acquired through cracks in the skin, causes a thickening of the outer layer of skin. Warts affect 7-10% of the population, and young people
are more commonly affected. Most warts are not worrisome, medically speaking, and are primarily of cosmetic concern except when causing discomfort,
particularly on the bottom of the feet.
Transmission Warts
are transmitted by direct contact or indirect contact
(e.g., public showers or swimming pool areas). They
can be transmitted to one's self or others. Picking
or scratching at warts can increase the risk of transmission.
Trauma may play a role in the development of warts as
they often occur at pressure points, for example, on
the bottom of the foot.
Types of Warts Each type of wart is caused by a slightly different virus and treatment may vary.
The common forms include the following:
Common warts (verruca vulgaris) are flesh-colored, small raised spots on the skin with a rough
surface. The
size of the wart varies and may appear anywhere on the skin, particularly on the elbows, knees, hands, fingers and around the nails. The black dots
found in these warts, often called seeds, are superficial blood vessels and not actual seeds. See
images.
Plantar warts (verruca plataris) are no different than common warts except that their location on the bottom
of the foot may result in a flat appearance from being pressed into the foot by the weight of the person. Plantar warts may occur singly or in a
pattern, grouped closely together. They may cause pain, redness and swelling.
Flat warts (verruca plana) have a smaller, smoother surface than common warts. They are often found in great
numbers on the face but may occur elsewhere, particularly on the arms and legs. See
images.
Genital warts (condylomata accuminata) may be small or large. When large, they may have a cauliflower-like
appearance. They grow on warm, moist surfaces such as the genital and rectal areas. They are usually, but not always, sexually transmitted. Do not
treat genital warts yourself; medical treatment is necessary. These warts are commonly treated with weekly applications of podophyllin, liquid
nitrogen or other agents, which may be irritating to the skin. Genital warts are common, contagious and may be difficult to eradicate. For more
information, see:
Self-Care You
can treat warts, except genital warts,
without visiting a doctor. Apply salicylic acid liquid
or plasters (available without prescription) according
to package directions. If using liquid, cover the wart
with a waterproof adhesive tape like duct tape or white
athletic tape. After 2-3 days, soak the area in warm
water, then scrape away the dead gray/white skin with
a pumice stone or metal nail file. Repeat until the
wart has disappeared.
Duct tape alone as an occlusive dressing has been effective at resolving warts. See article on "Duct Tape More Effective than Cryotherapy for
Warts" in the American Family Physician Journal.
If the wart does not completely disappear, see a clinician for medical treatment.
Medical Treatment Warts often disappear spontaneously over several years. If warts are
painful, subject to infection or cosmetically objectionable, they should be treated. Treatment depends on the size, location and number of warts as
well as the activities of the infected person. Warts may be very difficult to cure; often multiple treatments are needed, and even then treatment
success cannot be guaranteed. Types of treatment include the following:
Cryotherapy (liquid nitrogen) is used on many warts at UHS. First, any dead skin surrounding the wart may be scraped off. Next,
liquid nitrogen
is applied, producing an uncomfortable blister within two days of treatment. Many warts require more than one treatment with the second treatment
being performed 2-4 weeks after the first.
Cantharidin is also a blistering agent. It is occasionally used at UHS. It is painless when applied but within 24 to 48 hours an uncomfortable
blister develops. Use of aspirin or Tylenol in conjunction with elevating the blistered area helps reduce discomfort. Cantharidin is painted on the
wart which is then covered with moleskin or tape. This should be washed off in 4 hours (sooner, if irritating). In approximately 5-10 days, the
blister dries up and peels off, removing the wart. Some warts require only one treatment. This treatment may be effective for warts around the
nails.
Electrodessication (electrocautery) is usually used only after warts have not responded to other procedures. It consists of burning the wart with
a high frequency current, followed by scraping the surface. It should be used cautiously as it may occasionally cause scarring. This process is
rarely used at UHS.
Salicylic acid is often used for plantar warts. A 40% salicylic acid plaster is cut to the size and shape of the wart and covered with an occlusive
tape (e.g., duct tape). Alternatively, a 17-20% liquid may be applied. After 24 hours, the wart is pared down. This is repeated every day if the
area is not too irritated. This method may be used at UHS. Salicylic acid is also available without prescription; follow package directions and do not
use on genital areas.
