Plantar Warts Overview
Warts are the most common infection of the skin caused by a virus. Plantar warts grow on the plantar, or bottom surface of the foot. They tend to be found in areas of pressure such as the heel and ball of the foot. Plantar warts often grow into the deeper layers of skin because of the pressure they receive because of their location.
Generally, warts go away on their own with time, but plantar warts should be treated to lessen symptoms, especially pain, to decrease duration of symptoms, and to reduce transmission to others. Because the incubation period for warts is from 1-20 months, it is difficult to tell exactly when the virus was introduced into the body.
Plantar warts may cause pain, particularly when walking. They may spread to other sites. They do not, however, usually spread to areas that are a different kind of skin. In other words, plantar warts do not spread to the genitalia.
- In the United States, 7-10% of people have warts.
- Plantar warts are seen in all age groups, but they are most common among children aged 12-16 years.
- Use of public showers
- Skin trauma
- Weakened immune system because of certain drugs used or illness
- Plantar Warts Causes
- The human papilloma virus (HPV) causes plantar warts. The virus attacks the skin through direct contact. Normally, antibodies in the blood kill the virus. Some people are more susceptible to the human papilloma virus than others.
- The HPV takes refuge in the skin. This occurs through breaks in the surface of the outer layer of skin called the epidermis. Such exposure is frequently associated with public shower rooms or walking barefoot on dirty surfaces or littered ground where the virus is lurking.
Plantar Warts Symptoms
- Foot pain – Feels like a lump under the foot
- Leg or back pain – Possibly causes poor posture
- Firm, warty (rough, bumpy, and spongy, some appear thick and scaly) lesions with tiny pinpoint dark spots inside (not always apparent)
- Smooth surface with a gray-yellow or brown color
- Located over areas of pressure or bony point such as the heel and ball of the foot
- Usually flat because of pressure
- Several warts fusing to form mosaic warts
When to Seek Medical Care
Call your doctor if simple home therapy fails to resolve the problem. Usually a primary care doctor can adequately treat plantar warts. If treatment under a physician’s care fails to work satisfactorily, a referral to a dermatologist (a skin specialist) may be necessary.
Warts will appear over a relatively short period of time in an area where no callus tissue has been noted before. Corns and calluses usually develop very gradually over several years. It is wise to consult a physician when you are unsure whether you have a plantar wart or another condition, such as a corn, callus, mole, or skin lesion.
Most such growths are harmless, but some can become cancerous. It is also possible for a variety of more serious lesions to appear on the foot, including malignant lesions such as carcinomas and melanomas. Although rare, these conditions can sometimes be misidentified as a wart.
- Seek medical attention for these conditions:
- You or your child have warts and want them removed.
- Severe pain, redness, swelling, bleeding, or large lesions develop.
- After removal by a physician by various methods, including freezing or burning, signs of infection
- appear at the treatment site. If the area becomes red, hot, painful, and tender after treatment, an
- infection may have set in.
- After treatment, fever develops.
- Warts don’t disappear completely after treatment.
- Other warts appear after treatment.
Plantar warts are rarely an emergency; however, the complications of aggressive therapy can be. Bleeding, severe pain, inability to walk, redness, swelling, streaking, and boil or abscess formation can all indicate an emergency.
Exams and Tests
The diagnosis is typically made by observing the wart. If in doubt, the physician may send a simple scraping to a pathologist for examination.
The doctor may consider other problems, such as corns, calluses, or black heel (ruptured capillaries).
Plantar Warts Treatment
Self-Care at Home
Warts generally go away on their own within months or years. Because of the discomfort associated with plantar warts, removing them is usually the best course of action.
- For temporary relief of pain, place a doughnut-shaped piece of moleskin around the wart. You can buy this at the drug store.
- Plantar warts thrive on moisture, so keep your feet very dry. Wear socks made of a moisture-wicking synthetic such as polypropylene (or you can use cotton and change socks frequently). Change your socks twice a day and apply a medicated foot powder such as Zeasorb.
To remove warts yourself, you may try home treatments usually applied directly to the wart. Note that all of these methods can take considerable time to work, often months. Treatment should continue until the wart has disappeared or complications such as pain or infection occur.
- Salicylic acid
- To kill the wart, apply an over-the-counter salicylic acid preparation, available at the pharmacy in liquid, gel, pad, or ointment. Some familiar brand names are Dr. Scholl’s Wart Remover, Compound W, Freezone, and Wart-Off. Be sure to follow package directions because overapplication of these products can burn the skin. Periodically sand and re-treat the wart. It can take several months to get rid of a large one. Warts can spread, so monitor your feet closely and treat warts when they are small.
- Soak the affected area in warm water for 5 minutes before applying the salicylic acid. This will enhance the effects of the medication.
- Remove any loose tissue with a brush, washcloth, or emery board and dry thoroughly. It is also important to file away as much of the overlying callus tissue as possible so that the medication can penetrate the wart properly.
- In general, you should see improvement in 1-2 weeks. If such treatment does not yield results after several weeks, you should see your doctor for more aggressive methods of wart removal.
- The prolonged use of this medication is not recommended, especially in infants, people with diabetes, and others with impaired circulation.
- Do not use salicylic acid on moles, birthmarks, or warts with hair growing from them, genital or facial warts, or warts on mucous membranes, irritated skin, or any area that is infected or reddened.
- A commercial preparation containing about 17% salicylic acid and 17% lactic acid in a fast-drying solution (for example, Duofilm or Dermatech Wart Treatment) is applied daily after showering. The preparation is allowed to dry and the wart covered with waterproof tape, which is removed after the next shower or bath. You can pare the wart once a week with a sharp blade (or a family member can do it for you). It may take many months to clear the wart with this method.
- A mixture of 20% Formalin in aqueous solution, available by prescription, is applied daily after showering. The wart is pared once a week with a sharp blade. It may take many months to clear the wart.
- Hot water or hyperthermic treatment
- The affected area is immersed in hot water for 90 minutes daily. It may take many months to clear the wart.
- Vitamin A
- Another option is to apply vitamin A once a day by breaking open a capsule and squeezing the liquid onto the wart. It can take anywhere from 1-9 months for warts to disappear using this method.
Doctors may choose from several different techniques for removing plantar warts.
- One of the most common methods is to burn warts off with a mild acid applied topically to the wart. This disintegrates the viral cells and allows normal healthy skin to replace them. Many applications may be required over the course of several weeks to achieve this, but the technique is highly successful. Salicylic acid, cantharidin, and dichloroacetic (or trichloroacetic) acid are useful.
- Other acid methods may be used.
- Upton’s paste: A piece of thick adhesive tape (such as Leukoplast), with a hole cut in the middle for
the wart, is applied to the sole to isolate the wart. Upton’s paste is applied to the wart, and the whole area is covered with a second piece of tape. This is kept dry and intact for 1 week. The wart is then pared (shaved down) and the paste reapplied until clearance occurs. Upton’s paste consists of 6 parts salicylic acid and 1 part trichloroacetic acid in glycerin, mixed to a stiff paste (ordered by prescription).
- Salicylic acid in white soft paraffin: A mixture of 40-60% salicylic acid in white soft paraffin is applied daily after showering and covered with waterproof tape. You pare the wart once a week with a sharp blade.
- Formalin soaks: The doctor prescribes Formalin BP solution 37% and instructs you to make up a 3% solution on a daily basis. This is done by adding 2 teaspoons of the solution to 1 cup of water. Soak the affected area in a shallow dish for 20 minutes daily. Before treatment, Vaseline is applied between the toes and the normal skin surrounding the wart. Once a week the wart is pared with a sharp blade.
- Efudex (5-fluorouracil), although not an acid, is another topical ointment that can destroy wart tissue in a manner similar to chemotherapy for skin cancer.
- Laser treatment: New technology has enabled doctors to use lasers to kill the virus in warts. The procedure, sometimes performed in the physician’s office, is effective, clean, and accurate. It is also expensive. Some doctors shy away from laser treatment for warts because the benefits are not dramatic enough to warrant the cost.
- Cryotherapy : Freezing warts with a very cold solution such as sodium nitride can kill the virus. This causes the wart to turn black and eventually fall off within a few days. Cryotherapy works well on many parts of the body, but it is sometimes ineffective on plantar warts because they tend to run deep, and the cold may not penetrate far enough to kill the virus completely.
- Debridement : In this technique, the physician uses a scalpel to cut the warts off under anesthetic. It is often the procedure of choice when many small warts are present in a particular area. It can also be used in combination with acid to make sure the virus is killed and to prevent the warts from regrowing. Note: Cutting the warts out is generally not recommended for plantar warts because the surgery may leave a painful scar. It is common for warts to return in the scar tissue.
- Oral medication: No oral medication has proven effective.
- Immunotherapy : For plantar warts that are resisting treatment, you may be referred to a dermatologist for immunotherapy in which your body is taught to reject foreign substances.
- Avoid walking barefoot, except on sandy beaches. Use shower thongs or sandals, particularly in public shower rooms.
- Change shoes and socks daily.
- Keep your feet clean and dry.
- Check children’s feet periodically.
- Avoid direct contact with warts from other people or from other parts of the body. Don’t touch warts on other people. To keep from spreading warts, don’t scratch them. Warts spread readily to small cuts and scratches.
- Do not ignore growths on, or changes in, your skin.
- Prevention consists of avoiding sharing socks, shoes, and showering facilities.
- Protect the skin from injury and wash hands frequently. Warts should be covered with waterproof tape in wet environments such as showers and swimming pools to avoid infecting yourself or others.
Regardless of the home treatment or medical treatment used, a cure is not guaranteed. Warts may reappear at any time. Most therapies require several treatments and strict adherence to them. Work with your doctor or dermatologist to determine which therapy is right for you.
- In up to 60% of cases, plantar warts go into “spontaneous remission.” The wart subsides and disappears because of the action of the body’s immune system. However, plantar warts, left untreated, can (rarely) lead to precancerous lesions.
- Untreated, plantar warts may grow up to an inch across and spread into clusters.
- A painful scar on the sole of the foot can pose an even more severe problem, which is why surgery is not the first choice of treatment.
- Many of these viruses die within 1-2 years, and the warts they produce simply disappear. While they last, though, the warts are ugly, irritating, and often painful. For these reasons, many podiatrists (foot specialists) recommend having plantar warts removed.
- Warts can grow back. This indicates a virus is still in the body and growing. However, this is not cause for undue alarm. The virus that causes plantar warts is relatively harmless and causes few problems. Warts can spread to other parts of the body, particularly if scratching a wart causes it to bleed. Blood from a wart contains the virus and can cause a new wart to grow in an area that it touches. Therefore, it is important that warts be treated so they can be eliminated as quickly as possible.
- Infection, pain, and scarring may result from overly aggressive home therapy penetrating beneath the skin surface or epidermis. Pain can spread to other sites, and warts can be transmitted to others because of ineffective treatment.