Warts are caused by a virus known as the papova virus.  This virus is transferred by physical contact and enters the skin directly.  The virus has a long incubation period ranging from 1 to 20 months, meaning that it may take some time before a person will even notice its' presence.  One theory suggests that the virus is able to enter the skin at areas where the skin has sustained recurrent damage.  Examples include excessive perspiration on the feet and hands, areas of callus and nail margins in people who constantly bite their nails.

The term plantar wart simply refers to the location of the wart.  In this case, plantar refers to the bottom, or plantar aspect of the foot.  Plantar warts, which are also called verrucae, are a common nuisance that seem to have a predilection for the hands and feet. For sake of conversation, we'll just call them warts.

Warts are saprophytic, meaning that they need something (or someone) on which to live.  We have yet to determine why the papova virus prefers some individuals to others.  For some reason, children in their teens are particularly susceptible to warts.  Warts are seen less often in infants and adults.  It seems the papova virus is able to 'fly under the radar screen' of an adolescent's immune system.   Is it diet related?  Is adolescence so overwhelming to the immune system that the papova virus is not recognized as  foreign tissue? In the near future, studies in immunology should shed some light on the papova virus and help us understand some of the changes we see in our immune systems as we age.

Treatment of warts, plantar warts and verrucae

There's probably more ways to treat a wart than any other condition in medicine.  That implies that not one method of treatment is superior to any other method.  But, please remember that this is a self-limiting condition meaning to say that most warts do resolve on their own over time.  I know this doesn't help someone who is in pain, but bear in mind, treatment methods have changed dramatically over the past few years.  Many physicians are becoming much more conservative with their treatment methods.

Old treatment methods focused on the fact that the wart tissue was bad and bad tissue needs to be destroyed.  Freezing (cryotherapy), hyfercation (burning), and surgical excision were commonly used methods of care.  Each of these would cause pain; not a particularly great way to build a doctor patient relationship with a child.

Bearing in mind that these lesions are self limiting, many of the new methods of treatment focus on simply changing the environment in which the wart lives.  If a wart seems to like you, it's perhaps time that you change.  There's many ways to accomplish this.  Some methods are internal and others are external, some employ a combination of both.

Vitamin A is a common medication used to change the internal characteristics of the skin.  Vitamin A has been shown to clinically change many skin conditions including acne, wrinkles and warts.  Vitamin A is a fat soluble vitamin, meaning that it is dissolved and stored in body fat.  In the subcutaneous space, that area just beneath the lowest layer of skin, all of us have a layer of body fat for warmth, possible fuel (stored as fat) and storage of important minerals we use on a daily basis.  Vitamin A seems to provide a supporting role for skin.  And in the case of warts, vitamin A appears to alter the nature of the skin to a degree that the skin becomes inhospitable to the wart.  Subsequently, the papova virus dies.  Do be careful when using vitamin A which may be toxic in large doses.  Most texts recommend a dose of 20,000 to 30,000 units daily for a period of three months.

Externally there are a number of different methods of treatment used, but once again, most focus on changing the external environment of the skin.  Topical acids in conjunction with periodic debridement are popular and work well for many patients.  You may also employ a drying agent to decrease perspiration of the foot.

A popular new medication used to treat resistant warts is called Aldara (5% Imiquimod cream).  Aldara reduces the DNA of human papilloma virus subtypes 6 and 11 by the increase in production of cytokine.  Aldara is currently FDA approved for the treatment of external genital and perianal warts (subtypes 6 and 11).  Although the use of Aldara is considered 'off label' use when used for warts of the hand or foot, many dermatologists and podiatrists are now trying Aldara for resistant warts of the hands and feet.  Aldara is used under occlusion, meaning that the medication is applied and then covered with a plastic occlusive wrap.  The cost of Aldara is a significant consideration when considering its' use.  Most contemporary dermatologists consider Aldara as a method of treatment only used for cases of resistant warts.   

In resistant cases, a CO2 laser is effective in removing large areas of virus.  The CO2 laser is helpful in defining the margin between the wart and adjacent healthy skin, subsequently resulting in less post-op scarring.  This procedure requires a local anesthetic and does result in some degree of short term disability due to limited post-op pain. 

Other methods used to treat warts include;

Stippling - the lesion is anesthetized and a fine needle is used to pierce the wart over and over.  This method destroys the vascular network within the wart.

Injections of neoblastic agents - Bleomycin and 5-flurouracil have been injected directly into the wart.  These agents act as chemotherapy for the wart to arrest its' growth.

Tagemet - By coincidence, folks taking Tagemet for stomach problems find that it does have an effect on warts.  Most literature suggests 1200mg daily in divided doses.

Tea tree oil - This is a popular alternative approach.  Tea tree oil is available in most health food stores and is applied daily to the lesion until it is gone.

Topical vitamin A - Topical application of vitamin A has worked for many.  Some break open a vitamin A gel cap or even use cod liver oil topically.

Half a potato - I mention this folk remedy because it has worked for many people.  Rub a half of a potato on the wart and bury it in the back yard.  Obviously, the power of suggestion is effective in treating warts.

Cryosurgery - freezing the wart is popular.  It works well for lesions in areas of thin skin such as the top of the foot or hand.  The thickness of the palm or sole does limit the effectiveness of this method.  Cryosurgical methods work by forming a blister beneath the wart.  This technique can be painful for some patients.