While many warts resolve without treatment, therapy may be required when plantar warts are painful or affect a patient’s ability to walk. Accordingly, this author discusses his clinical experience with a variety of modalities ranging from pulsed dye laser therapy and topical treatments to surgical excision.
Warts are the most common viral infection of the skin and they are most often caused by human papillomavirus (HPV) type 1. There are more than 120 different varieties of HPV and only certain varieties are the cause of warts. Certain virus types tend to infect specific anatomical areas such as the plantar surface of the foot. At least 50 percent of adults will be infected with verruca during their lifetime.1 Although the current prevalence of plantar warts in adults is unknown, plantar warts have been estimated to occur in 7 to 10 percent of adults.2
Plantar warts can occur anywhere on the bottom of the foot but tend to produce symptoms in parts of the body that experience pressure and friction.
The HPV virus infects only the superficial layer of skin and produces a thickened, callus-like growth. If this growth is located in an area subjected to pressure, it can become tender. Certainly, warts can present with much variety in size and depth, but they do not go below the basement membrane of the skin.
Characteristically, warts resolve spontaneously although one may need to treat warts that affect the patient’s ability to walk or warts that cause pain. The incubation period of verruca is unknown but may last from months to years. However, I have found that when people think they stepped on a foreign body, this can be a route of entry for the infection.
Inoculation of the skin usually occurs when one comes into contact with others infected with plantar warts. This contact may occur in areas like showers or pool areas. The mechanism of action for spontaneous resolution of the warts seems to be dependent on developing immune lymphocytes that kill the virus infected cells. It is likely that the levels of neutralizing antibodies in the blood induced by inoculation with HPV proteins can protect against related infections.
Determining Initial Treatment Options
Generally, when a patient comes into my office for treatment of verruca, I look at a few variables that bring me to my treatment protocol. These variables are as follows:
• age of the patient;
• duration of the wart;
• number of warts;
• pain tolerance of the patient; and
• presence or lack of pain with the warts.
Once I consider these factors, I explain all of the treatment options for the individual patient. I explain to the patient or parent that warts are caused by the HPV virus. (As I am sure you are aware, not too many patients understand this unless they search it on the Internet.) I then explain that it takes weeks or even months to eradicate warts. Of course, if the patient opts for surgical excision by cold steel or the use of a CO2 laser, then this would be a quicker “cure.”
Of course, as we all know, there really is no true cure. We must stress to the patients that if they get a wart, they are more likely to get more warts or have recurrence.