Warts and Verrucas

Written by Magdalena Czerwiec-Pichlińska

A verruca is one of the most common viral infections presented not only on the feet, but also on different parts of the body. It is often said to be more common among children and adolescents, but in fact can occur at any age. It is a benign tumour, which is caused by infection of epidermal keratinocytes double stranded DNA Human Papilloma Virus (HPV). The research shows that there are between 100 and 200 different types of plantar warts, each caused by a different subtype of HPV. The most common are HPV1, HPV2, HPV4, HPV27, and HPV57. They cause different clinical features and can infect different body sites.

Once the virus gets into the body it will stay there for a lifetime, hence there is no guarantee that once cleared it will not appear again. Usually, it takes between 1 to 8 months to develop a verruca. Every time the individual’s immune system is suppressed (for any reason) it can trigger the HPV to activate.

The virus affects the outermost layer of the skin, the epidermis, by replicating and changing the structure of the cells filling them with fluid. In the stratum spinosum of the epidermis, the number of cells increases, this process is known as hyperplasia. This can result in an increased localised bulk of tissue within the skin.

The altered cells replicate and then migrate to the surface, proliferating and altering the epidermis. Swollen cells create a hard lesion, which presses on the surrounding tissue and the dermis itself causing pain and micro-bleeding into the epidermis (hence we can often spot black dots on the tumour). The blood is separated from phagocytic cells, which are responsible for degrading it. This results in the transit through the epidermis.

Since HPV activates anti-inflammatory T suppressor cells and changes Langerhan cell function, the immune system does not detect it and can therefore not fight it off.

The spread of the lesion is impossible to predict as it depends, among other factors, on the
individual’s susceptibility to the virus.

An established verruca commonly appears as a wart with a rough, cauliflower-like surface. Sometimes the verruca can have a black dot in the centre. In the early stages a verruca can often look like a corn and is quite often mistaken for a corn.

The verruca itself looks as if it is encapsulated in the skin and when pinched gives sharp pain. An intense throbbing pain can be felt after standing on the foot and then off-loading.

Verruca warts can vary in appearance, depending on the type of HPV involved.

• HPV1, HPV27, and HPV57 cause single, deep plantar warts with a rubbery appearance. They are usually very painful.
• HPV2 is responsible for mosaic warts, generally less painful than the single ones. They are scalelike and present in a large area.
• HPV4 causes multiple lesions which do not usually cause pain.

Human papillomavirus (HPV), like many other viruses and bacteria, resides on the skin surface all the time. The problem begins when it gets inside the body through micro scratches, like for example rough tiles in and around public swimming pools.

Most common disinfectants can eradicate HPV. Although HPV is highly contagious, in order for HPV to get into an individual’s body it needs the surface of the skin to be broken, so as to allow the virus to get into the epidermis.

Exposure to the virus can occur in a variety of places, most commonly communal, barefoot environments, such as in school or sports changing rooms.The virus gets into the body through walking on the rough, infected surface, through grazes, or any other contact with open skin.

Once the virus enters the body it stays there for a lifetime, so there is no guarantee that it will not reappear. The development of a verruca usually takes between 1 and 8 months. HPV is triggered every time the immune system of an individual is suppressed.

A verruca can be diagnosed by a Foot Health Practitioner, podiatrist or doctor. It can be diagnosed by its appearance and by palpation (is it painful when squeezed?).

Your Foot Health Practitioner will diagnose the verruca by taking a thorough medical history from the patient.They will then examine the lesion visually and by touch. Verrucas vary in appearance, from completely painless and small lesions, to wide, spread around the foot and extremely painful. It is important to diagnose the wart correctly as they are often mistaken with seed corns or heloma durum (corns).

One of the common methods for diagnosing a verruca is by using a gentle lateral squeezing technique – if sharp pain occurs it is very likely to be a verruca. Although it is necessary to remember that some of the vascular corns give the same symptoms and some of the verruca types don’t give this symptom at all.

Experienced practitioners will check if the dermatoglyphics structure is intact, this refers to the lines, ridges and surfaces of the skin. Due to the verruca causing a bulk of tissue, this can result in a disruption to the dermatoglyphics. The mass of vacuolated (engorged) cells disrupts the surface ridges and furrows, so that the dermatoglyphics are seen to be pushed away from the surrounding lesion.

A verruca is a curable condition and there are many treatment options, although no methods can provide a 100% guarantee of healing. This is mostly because it is the individual’s immune system that is responsible for combating the virus. This means sometimes it can spontaneously resolve within a few years. It takes up to 8 months from the virus entering into the epidermis to develop the lesions, and as it went in unnoticed, it can resolve itself unnoticed within that time, especially among the young and healthy individuals. Therefore it is not recommended to treat verruca in children until there are issues of pain or self-consciousness. Although verruca is caused by HPV, there is no effective vaccination to prevent plantar warts. The vaccination children receive at school protects them from the different strains of the virus.

Apart from home remedies, some of which may work as a placebo, there are a few clinical home remedies that can work in treating a verruca. The ideal way is to improve the individual’s immune response, manage the patient’s expectations while remembering that no treatment is guaranteed to be a 100% success, and use a painless method without creating scars.

The practitioner has a wide range of treatments to choose from, such as using salicylic acid, Verrutop, cryotherapy, swift and laser (heat therapy), and needling. The aim of all the different treatment methods are to alert the individual’s immune system and activate the natural defence and healing response.

Salicylic acid dries out epidermal moisture and “shrinks back” the verruca. It requires several weeks of daily application to work and may cause damage to healthy tissue.

Verrutop is a nitri-zinc complex solution, which consists of nitric acid, metallic salts (zinc and copper) and organic acids (oxalic acid, lactic acid and acetic acid). Nitric acid reacts with amino acids in the skin and dehydrates proteins and the cellular matrix. During this process xanthochromia occurs (skin is being stained yellow) and a noxious gas is released. This dehydration of the tissues `shrinks` the lesion and breaks down protein bonds in viral-infected keratinocytes. This treatment is widely considered as the most effective and safest form of treatment for verrucas. Verrutop has to be applied by a professional due to the precision needed to avoid damaging surrounding healthy tissue. Effects are usually seen after 4 applications, and the treatment can be applied up to 6 times.

Cryotherapy consists of freezing the lesion with liquid nitrogen. The aim is to damage the affected tissue and cause an anti-inflammatory response. However, this method may leave a scar. It is a very painful method, therefore it is not used on children, as the pain can be unbearable for them.

Laser therapy and microwave therapy both are heat therapies with the aim similar to cryotherapy – damaging the infected tissue. It can cause burns and leave a scar similar to cryotherapy. Swift (microwave) is considered to be safer than laser and seems to be more effective although currently there is not enough research to confirm.

Needling is another way of causing trauma to trigger an immune response. It does not involve chemicals. The needle penetrates the full depth of the verruca and perforates the lesion.

Occlusion therapy is a therapy that covers the lesions with zinc-oxide tape to cause maceration of the skin. The main aim is to induce inflammation and an immune response. This method requires time and consistency.

Once HPV enters the body it will remain there forever, but can be dormant and not cause any problems. As the immune system is the one responsible for fighting the virus it is possible that without any treatment warts disappear as suddenly as they occur.

Verruca can be prevented by following hygienic advice. The basic advice is:

• Avoid walking barefoot in communal places such as a swimming pool or gym
• Change hosiery every day
• Regular disinfecting of floor surfaces
• Avoid micro injuries or scratches on the surface of the skin.

In general there is no need for hospitalisation for a verruca, although it is recommended to contact your GP if the warts are especially persistent, painful and if your body is not reacting to the different treatment options.

Usually there is no need for the hospital treatment, but when the verruca is disrupting the individual’s life, causes pain or affects self-confidence then it is recommended to seek the help of a Foot Health Practitioner to help rule out a different diagnosis. On rare occasions it could be a more serious condition – if this is the case you will be referred to the dermatologist for further examination.