Plantar Warts

Overview

Warts are benign, rough growths that appear on the skin as a result of a viral infection. These can be quite uncomfortable, unsightly and even painful, especially when located in areas such as the sole of the foot which can make it difficult to walk normally. Although warts are not especially harmful and often go away by themselves without leaving behind scars, it should be borne in mind that they are contagious. The virus can enter the body through cuts and breaks in the skin. Hence one should avoid touching warts unnecessarily and take care to wash one’s hands immediately afterward.

However, contact with the human papillomavirus (HPV) does not always result in the formation of a wart. Given the right kind of environment, such as a combination of moisture and warmth, the virus can thrive and cause a wart to appear. A plantar wart or a plantar verruca is one that appears on the sole of the foot, typically on the heel or the balls of the feet. Only some strains of HPV are capable of causing warts in these locations.

What Are Plantar Warts?

A plantar wart is a rough and bumpy growth in the skin of the sole of the foot. It is a benign growth caused by infection with certain strains of the human papillomavirus (HPV). This infection can be acquired by making contact with another wart, with the debris of infected skin or with objects that have made contact with infected skin.

Plantar warts can appear individually or in the form of clusters. This is a minor affliction and often resolves on its own without any lasting damage to the skin. When it doesn’t, it can be treated effectively by means of medications or even a minor surgical procedure. The bump is usually present beneath a hardened layer of skin called a callus and shows darkened spots in the center. Although it can spread to other areas and cause more warts to appear. This kind of infection remains superficial and confined to the epithelium of the skin.

Why Do They Appear?

The direct cause for the appearance of a plantar wart is HPV infection, usually acquired by direct or indirect contact with an infected site. The virus enters through cuts or abrasions in the skin such as the cracked heels of the foot. If there is moisture trapped in these spaces, it increases the chance of developing a wart. The list below enumerates causes and risk factors associated with plantar warts:

• The virus can pass from one person to another through direct skin-to-skin contact with the infected site.
• The infection can also be acquired by touching objects that have made contact with an infected site. For instance, towels, footwear or personal hygiene products used by a person who has such a wart can also carry the virus.
• Having cuts or breaks in the sole of the foot allows the virus to penetrate the skin.
• The presence of warmth and moisture. Spending long periods of time wearing closed footwear traps perspiration and maintains the warmth that provides an ideal environment for the virus to thrive in.
• A plantar wart is more likely to arise in those parts of the sole that experience a lot of pressure or friction. This is why they frequently appear on the heels or the balls of the feet.
• Children are generally more likely to develop warts than adults.

What Are The Signs and Symptoms?

Warts do not appear immediately after infection with the virus. This usually takes a few weeks or more. Warts occurring in other locations such as the face or hands may show a rough and irregular texture and protrude visibly from the surface of the skin. However, a plantar wart is more likely to have a flat surface especially if it is situated on the skin of the heel or the balls of the feet.

These areas have to bear a great deal of pressure as a result of which the wart is typically pushed inwards instead of protruding outwards. The formation of a wart involves localized hyperkeratosis or abnormal thickening of the skin and it can be identified by the following signs:

• A bumpy growth on the surface of the skin, often beneath a thick and hardened callus. These are usually lighter than the surrounding skin. Some warts may show fissures and the natural ridged pattern of the skin is disrupted by the wart. Plantar warts may appear singly or in clusters. These may fuse together and form a mosaic wart.
• Petechiae or fine, dark spots in the center of the wart as a result of broken and clotted blood capillaries.
• Pain or discomfort may be experienced when placing pressure on the site of the wart.

Can Plantar Warts Give Rise To Any Complications?

It is possible for the infection to spread to other sites and produce similar warts. One should seek medical assistance particularly if the wart causes pain or bleeds or it tends to reappear frequently.

Even after it has been treated, a wart can reappear in the same location if the infected layer of skin was not completely removed on the first occasion.

Recurrence is more likely in persons with reduced immunity and such patients are also more likely to have large, widespread wart formations.

Other complications can arise as a result of aggressive therapy. There may be scarring, pain or bleeding at the site of the treatment, making it difficult for the patient to walk.

How Are Plantar Warts Diagnosed?

A plantar wart is clearly identifiable by means of physical examination. Laboratory tests or complex imaging are not normally required. The presence of small black dots, or petechiae, in the center of the wart, is a defining characteristic and helps differentiate a wart from other hyperkeratotic lesions such as corns. Superficial layers of hardened skin may need to be trimmed off in order for these petechiae to become more apparent. Further, the natural ridged pattern of the skin is interrupted by a wart but continues across the surface of a corn. This is another differential sign to look for.

A certain form of cancer known as squamous cell carcinoma can resemble a particularly large and advanced plantar wart. Biopsy confirms whether or not the lesion is a mere wart or a sign of malignancy.

Treatment & Prevention

The following treatment methods have been proven to be effective in getting rid of plantar warts:

• Acid treatment: This involves the use of mildly acidic ointments such as salicylic acid or Upton’s paste to burn the wart. It takes a time period of few weeks to successfully get rid of the plantar wart by this method. It is important to cover and dress the wart properly during the course of the treatment.
• Laser treatment: In this method, laser beams are used to remove the wart from the skin. This is a comparatively more expensive process and is likely to leave a scar on the affected skin.
• Cryotherapy: Liquid nitrogen is used to freeze the wart which then blackens it and causes it to fall off without leaving a scar.

Plantar warts can be easily prevented by adhering to the following guidelines:

• Keep your feet covered whenever accessing crowded public spaces such as swimming pools, locker rooms, dormitories etc.
• Keep your footwear clean and sanitized. Wear clean and dry socks.
• Check with your doctor if you can get vaccinated for the HPV.

References