Verrucas, verrucae or plantar warts are small lesions, rough lumps, warts or growths that are found commonly over certain areas of the feet like the heel and the balls of the feet that commonly bear pressure.
Verrucas usually resolve on their own but may need treatment if they cause symptoms. For example, around half of these will disappear within one year, two thirds go away after two years and the rest one third are persistent and resistant to therapy. 1-5
Causes of verrucae
Verrucas are caused by a viral infection by Human papilloma virus (HPV) types 1 and 2 and sometimes 4. This virus attacks the topmost layer of the skin or the epithelium. This causes the cells to proliferate or form a growth or a raised plaque. Sometimes it may take up to a year or two after the initial viral invasion for the lesion to show up. Verrucas are not cancerous.
Mode of spread
Verrucas are usually spread by person-to-person contact. Common modes of spread are sharing communal showers where other people with verrucas have also bathed. Infections are common if the skin of the feet are damaged or cut or ulcerated in any manner.
In addition spread may also occur if there is scratching, nail biting, shaving or finger sucking. This results in spread to different areas of the body of the same person.
How common are verrucas?
It is found that most people get these verrucas at some point in their lives. Women are slightly more affected than men. These are more common among children and teenagers affecting around 4-5% of the population but are uncommon in infants.
Some professions are more at risk of these warts that commonly affect the hands. These include butchers, abattoir workers, engineers and office workers.
Symptoms and signs of verrucae
Most people with verrucae complain of pain while walking. Pain due to verrucae of the pressure areas of the feet may lead to an altered posture during walking and this may lead to leg or back pain as well.
Families are affected but this disease is not inherited. It is highly contagious and more than one member of the family is affected at once.
Those with eczema, low immunity, diabetes, AIDS, who have received a transplanted organ and are on immunosuppressant medications and patients of leukemias and lymphomas are at a higher risk of this infection. Around 50% of people who have had a kidney transplant develop warts within five years.
The warts appear firm and may have pinpoints of spots over it. They are located on pressure areas such as heels or balls of the feet. The pressure makes them appear flattened. More than one wart may be fused to form a mosaic wart.
Diagnosis of verrucas
Diagnosis is made by clinical examination and also other conditions that mimic these warts need to be ruled out. These include:
- black heel
- verrucous squamous cell carcinoma (skin cancer of the feet)
- arsenic induced keratosis
- actinic keratosis
- cutaneous horn
- lichen planus
- lichen nitidus
- molluscus contagiosum
- seborrhoeic keratosis etc.
Treatment of verrucas
Usually there may be no treatment if not painful or symptomatic. In many patients steps for prevention of recurrence and spread are advised. Those who have a depressed immunity; painful warts; have persistent warts for over 2 years; or desire treatment, are candidates for treatment.
Treatment is with salicylate medications. These are available as gels, paints, plasters, colloidion etc. Other preparations contain formaldehyde and glutraldehyde. Some prefer cryotherapy or freezing the warts till they fall off. Rarely surgery and removal of the warts are undertaken. Injections of the verruca with interferon, 5-flurouracil, bleomycin etc. are other options.
Common complications include pain, secondary bacterial infections, scar formation etc. There may psychological impact of the verrucae especially in children. In patients with a depressed immunity there is a rare possibility of the verrucae turning into cancer.
Outcome of verrucas
In many patients there may be treatment failure and there is a high risk of recurrence. In addition, most disappear within two years without treatment and at least 90% of warts present at age 11 years, will be gone by age 16 years.
Prevention of verrucas
Patients are advised to wear waterproof verrucae socks to prevent spread. The verrucae should be covered with a waterproof plaster when swimming. Shoes and flip flops should be worn at community showers. Shows, socks or towels should not be shared. Scratching and itching should be discouraged to prevent spread to other parts of the body.
Reviewed by April Cashin-Garbutt, BA Hons (Cantab)