Verrucae are benign tumours caused by the Human Papilloma virus (HPV). The most common warts (aka “Verrucae” on feet) are the subtypes HPV1, 2 and 4.
HPV1 infection is responsible for the largest, most painful type of verruca. They do not go deepest into the tissue, but the skin cells involved become filled with fluid which in turn creates pressure in these cells so that when the infected area is trodden on, the pressure from the fluid and our body weight makes the verruca feel painful.
HPV2 infection gives rise to “MOSAIC” Verrucae, so called because of the classic mosaic pattern with many individual lesions contained in one capsule. These contain less fluid so tend to be less painful.
HPV4 infection results in multiple small verrucae.
HOW DOES INFECTION OCCUR?
To become infected with the HPV virus, all that is needed is an abrasion of the epidermis (outer layer) of the skin, however this need not be a deep or clear cut, even a knobbly or rough tile or surface will cause a minor abrasion that is not visible to the naked eye but will allow infection to occur. Once in the epidermis, the virus can remain dormant for up to eight months, so if you wonder how you became infected if e.g. you haven’t been to the swimming baths for ages, there is your answer! As our skin cells follow the normal pattern of dying and being shed, so the virus is shed within them and waits to adhere to a new host.
HPV virus is present virtually everywhere on surfaces that people touch. Once within the epidermis, the virus replicates itself thus causing a proliferation of “prickle cells” which cause the epidermis to take on the warty/verruca appearance.
HOW DOES THE VIRUS AVOID THE IMMUNE SYSTEM?
There is very limited, if any, release of viral proteins meaning that there is very little, if any, antigen that can be presented to the host’s immune system. Also, the epidermis has no blood supply and as the virus doesn’t venture beyond this skin layer, the immune system (via the blood supply) is unable to detect it. The virus is also able to induce an altered local immune response by activating cells that suppress an immune reaction within the body.
WHAT IS “DRY NEEDLING” ?
Dry needling is where the area of the foot that carries the lesion to be treated, is anaesthetised, usually by a Tibial Nerve Block, so that 1 or more verrucae can be punctured with a hypodermic needle 100’s of times, forcing cells containing the HPV virus into the blood stream of the host thus enabling the body to detect the viral infection and formulate an immune response which will then clear the verrucae/warts.
Obviously the anaesthetic procedure is slightly uncomfortable, but once this has taken effect, needling is no more painful post treatment than many standard procedures such as freezing or caustic (acid) therapy, but the beauty is that only 1 or 2 lesions need to be treated even if there are multiple infected areas, because if the immune response is initiated then all lesions (caused by the same HPV type) will disappear regardless of whether they are on the hands, feet or both.
In theory if the person is exposed to the same HPV sub-type in the future then they should have immunity against it.
A sterile dressing is applied immediately post-op along with suitable padding to deflect weight bearing (depending on the location of the treated area), then a return visit is arranged 1 week post-op for dead tissue removal. The area is reviewed 8 weeks later by which time progress will be apparent if the treatment has worked. Full resolution should be apparent between 8 and 16 weeks.
NB: If resolution hasn’t occurred after 16 weeks then a second treatment should be considered.
The patient is able to resume all normal activity 24 hours post-op, having kept the area dry during that initial 24hrs.
Paracetamol is usually totally adequate as the pain management of choice if any discomfort is felt post-op. Aspirin is not advised as it discourages clotting.
AM I SUITABLE TO RECEIVE DRY NEEDLING?
Most people would be totally ok to receive needling therapy but patients who take e.g. Warfarin or other anti-coagulants, patients who are pregnant, patients who are immuno-compromised and the very young would be advised to try other forms of therapy.
Any patient considering needling therapy should desist from other forms of verruca treatment for 8 weeks before under-going the procedure.
Documentary evidence claims success rates ranging from 50 – 69%, which is easily comparable to freezing or caustic therapy, but the real bonus is that if multiple lesions are present then they don’t all need to be treated. Also, the time factor means that the patient doesn’t need to keep applying home treatment and/ or visiting a Podiatrist with great regularity.
The cost of Dry Needling initially appears expensive but it must be compared to the overall cost of multiple trips to a Podiatrist and any home treatments involved.
Richard Harris is able to provide this treatment if required via INSTEP of Oakham. For more information please call 01572 759209