Warts and all: diagnosis and treatment

Summer (what we had of it anyway!) is over and the kids are back to school. This means seeing new and old friends and going back to PE lessons.  Meanwhile many grown-ups may be heading back to the gym as the autumn chill sets in.  Both can be welcome changes but they can also bring less welcome a visitor in the home- the wart virus!

It’s thought that as many as 30% of children and young adults have warts.  They can be picked up by other children and adults, often from gyms, swimming pools and showers. They are usually only a minor nuisance, but they can be uncomfortable, especially on the feet, and can be very unsightly to look at.

Warts are caused by the human papillomavirus (HPV).  There are over 150 different types of HPV.  In addition to causing common warts HPV can also be associated with pre-malignancy and squamous cell carcinoma of the skin.

Diagnosis and Tests

Diagnosis is usually easy just by sight. A doctor or podiatrist may need to scrape away the dead skin on the surface to have a have a look at what is underneath.  Only occasionally is a biopsy needed, usually to distinguish it from something more serious such as a skin cancer.  Other tests are usually not required but very prolonged or severe warts might indicate an impaired immune system, which may prompt further investigations such as blood tests.

Treatments

Many warts do not need any treatment.  Warts in children can disappear spontaneously after only a few months, with half clear at a year and two-thirds by two years.  In adults they can take a lot longer and many can persist for 5-10 years

• Wart paints/gels

This is most common treatment when one is required.  They often contain salicylic acid and can be bought over-the-counter.  It is usually well tolerated but to make them more effective pare down the wart and soften it by soaking in warm water for 5-10 minutes.  Treatment needs to be done for at least 12 weeks but sometimes longer.  Cure rates are variable and depend on many factors including the site of the wart- only 1 in 5 on the hand and 1 in 3 on the feet might clear with 40% salicylic acid.

• Occlusotherapy

This is a very simple treatment that you can do at home and it can be very effective.  It involves applying duct tape to the warts for several weeks. You can get a clearance rate of up to 85% after 8 weeks of treatment.

• Cryotherapy

The next option is usually cryotherapy which involves freezing the warts with liquid nitrogen most commonly.  This needs to be done by a trained nurse, doctor or podiatrist.  It needs to be do be done over multiple sessions spaced 1-4 weeks apart.  Warts on the feet may need 8-12 sessions. Cryotherapy is generally more effective than salicylic acid but even then the results a very variable and the success rate might be only 50%.  If you combine this with salicylic acid though the clearance rate can be as high as 86%.  Cryotherapy can be painful and can cause blistering and skin discolouration particularly in darker skin types.

• Surgery

Warts can be cut out or burned away with a success rate of 67%.  However the recovery time can be quite long- in the order of several weeks for the feet.  Also the scar that develops might itself be painful particularly if it’s on weight bearing area.

• Laser

There are a number of different lasers used to treat warts.  These include pulsed dye laser, Nd:YAG laser and carbon dioxide.  Several treatments may be required usually around 2-8 depending on the type of laser.   They are often more successful than cryotherapy as high as 93% clearance rate.  The recovery is often shorter than with surgery.

• Photodynamic therapy

This involves applying a light-sensitive cream to the warts and then shining a light on to it.  The cream undergoes a reaction with the light and starts to destroy the wart.  This can also be very successful with up to 95% clearance rate.  It can be quite effective when combined with laser.

• Contact immunotherapy

This involves applying a chemical such as diphencyprone to deliberately induce a hypersensitivity reaction to it.  This stimulates the body’s own immune system to destroy the wart.  It needs to be applied twice weekly to every 3 weeks for 3-6 months and the success rate can be as high as 88%

Some home remedies such as garlic work on a similar principle of inducing the body’s immune response to destroy the wart

• Imiquimod

This is a prescription immune stimulator normally used for perianal or genital warts.

• Other treatments

There are a whole range of other treatments for warts.  These include different types of acid (citric acid, formic acid, glycolic acid), injections of bleomycin, formaldehyde, oral treatments such as zinc and cimetidine, homeopathy and even hypnotherapy! These may or may not work but at the moment there isn’t enough evidence to recommend their use in regular practice.  They might be useful as an adjunct treatment or if other treatments fail or are not tolerated.

So in summary, warts can be a real nuisance but there are lots of different ways of dealing with them so don’t suffer in silence!

Dr Nisith Sheth is a Consultant in the Dermatology Surgery and Laser Unit of St John’s Institute of Dermatology. He trained in the UK, Canada and the USA. He sees and treats all skin conditions.  Read more about Dr Nisith Sheth over on our About us page.