Types of Wart
Warts are benign skin growths caused by the human papillomavirus (HPV) — not the strains associated with cervical cancer, but separate, low-risk strains. HPV infects the outer layer of the skin and causes cells to multiply rapidly, producing the characteristic raised growth.
Common Warts (Verruca vulgaris)
Rough, raised, cauliflower-like growths most often on the hands, fingers, and knees. Greyish-white or skin-coloured with black dots (thrombosed capillaries) visible on the surface.
Plantar Warts (Verrucas)
On the soles of the feet, forced inward by body weight. Often painful underfoot, sometimes confused with calluses. Can spread rapidly and become large or multiple clusters (mosaic warts).
Plane (Flat) Warts
Small, flat-topped, smooth warts most common on the face, forehead, and backs of hands. Often multiple. Skin-coloured or slightly yellow. Can spread rapidly via shaving.
Filiform Warts
Long, narrow, finger-like projections most commonly around the eyes, nose, and mouth. Grow rapidly and can be disfiguring if left untreated.
Why Over-the-Counter Treatments Often Fail
Pharmacy salicylic acid preparations work well for many superficial warts — but they have limitations. They require consistent daily application for weeks to months, and they depend on the active agent penetrating deep enough to destroy the virus-infected cells. Common reasons they fail include:
- Plantar warts covered by thick callus — the acid cannot penetrate deeply enough
- Inconsistent application — missing days allows the wart to recover
- Mosaic warts covering a large area
- Immunosuppression reducing the body's ability to clear the virus
- Long-standing warts with deep viral infection
Clinical cryotherapy using liquid nitrogen is significantly colder than OTC freeze sprays (which use dimethyl ether/propane at approximately -57°C vs liquid nitrogen at -196°C) and achieves a much deeper freeze zone — typically the primary reason clinical treatment works when OTC products have not.
Clinical Cryotherapy: What It Involves
Your GP applies liquid nitrogen to the wart using a spray gun or cotton-tipped applicator. The freeze is applied for 10–30 seconds depending on wart size and location. This causes the wart tissue to blister and the virus-infected cells to die.
What to expect after treatment:
- The area may sting and throb for a few hours after treatment
- A blister may form over the following 24–48 hours — this is normal and a sign the treatment has worked
- The wart gradually darkens, dries, and separates from the underlying skin over 1–2 weeks
- In between sessions, gentle filing of dead tissue with an emery board helps maintain treatment progress
Most warts require 2–4 sessions at 2–4 week intervals to clear completely. Plantar warts often need more sessions due to the thickness of sole skin.
Other Treatment Options
For warts that fail to respond to cryotherapy, or in locations where cryotherapy is technically difficult, your GP may discuss electrocautery (heat destruction under local anaesthetic) or refer to dermatology for surgical excision or laser treatment. The choice depends on wart type, location, and your preferences.
Book Wart Treatment
Lambert Medical Practice offers private cryotherapy for warts and verrucas in Surbiton. Assessment and first treatment are performed at the same appointment.