Warts are small, non-cancerous skin growths caused by infection with the human papillomavirus (HPV). They can appear on the hands, feet, face, or other parts of the body, and while not usually dangerous, they are contagious and can be stubborn to remove.
At London Wart Clinic, our private doctors regularly see patients with warts that have persisted for months or even years, often after multiple rounds of home treatments. Understanding what causes warts helps explain why they spread, why some people are more prone, and why professional treatment may be required.
What Warts Are and What Causes Them
Warts form when HPV enters the skin through a small cut or abrasion and stimulates the outer layer of skin (epidermis) to grow more rapidly. This produces the rough, raised surface associated with warts.
- More than 100 strains of HPV are known, but only certain types cause common skin warts or plantar warts (verrucas).
- HPV is highly prevalent. A study in the British Journal of Dermatology reported that up to one-third of children and adolescents develop warts at some stage.
- The infection is spread by direct skin-to-skin contact or indirectly via surfaces like changing room floors or gym equipment.
Although harmless in most cases, warts can spread quickly, especially on the hands and feet, and can pass from person to person.
Risk Factors and Who Gets Warts
Not everyone exposed to HPV will develop a wart. Several factors increase susceptibility:
| Risk Factor | Evidence / Data | Notes |
|---|---|---|
| Age | Up to 33% of schoolchildren are affected (BJD, 2014). | Children and teenagers most commonly affected. |
| Skin breaks | Warts often form around nail-biting or shaving sites. | HPV enters through micro-abrasions. |
| Environment | Public swimming pools and changing rooms strongly linked with plantar warts. | Warm, moist surfaces support transmission. |
| Immune system | Warts are more common in people with weakened immunity. | Illness, certain medications, or high stress can increase risk. |
| Close contact | Families or classmates may share infections. | Direct touch spreads the virus easily. |
This explains why verrucas are so common in school-aged children in the UK, particularly during swimming lessons.
Symptoms and How to Recognise Warts
Warts vary in appearance depending on the type and location. They are sometimes mistaken for corns, calluses, or other skin lesions.
| Type of Wart | Appearance | Common Sites | Distinguishing Features |
|---|---|---|---|
| Common wart | Raised, rough, cauliflower-like surface | Hands, fingers, knees, elbows | May have black pinpoints (thrombosed capillaries) |
| Plantar wart (verruca) | Flat, hard, painful growth | Soles of feet | Painful when walking, often inward-growing due to pressure |
| Filiform wart | Long, thin, finger-like projections | Face, eyelids, lips | Grows quickly, stands out from skin |
| Mosaic wart | Cluster of small warts | Soles of feet | Multiple grouped lesions, often resistant to treatment |
| Periungual wart | Thickened growth around nails | Fingernails, toenails | Can distort nail shape if untreated |
A private dermatologist or surgeon can confirm the diagnosis and ensure it is not another skin condition.
Treatment Options and When to Seek Help
Warts sometimes resolve on their own, particularly in children, but this can take months or even years. In adults, many warts are persistent and may spread if left untreated.
Over-the-counter options:
- Salicylic acid (gels, paints, or plasters) can be effective but require daily use for up to 12 weeks.
- Freezing kits are available but generally less powerful than medical cryotherapy.
Professional treatments at London Wart Clinic include:
| Treatment | How It Works | When Recommended |
|---|---|---|
| Cryotherapy | Wart is frozen with liquid nitrogen, destroying infected cells. | Commonly used for small or stubborn warts. Requires repeat sessions. |
| Cautery (Electrosurgery) | Heat is applied to burn away the wart. | Suitable for resistant warts or those causing pain. |
| Laser removal | Focused light energy destroys wart tissue. | Reserved for resistant or multiple lesions. |
| Surgical excision | Wart cut out under local anaesthetic. | Rarely needed, but effective if other methods fail. |
If a wart is painful, spreading, changing in appearance, or resistant to home treatment, it may be time to see a private doctor. London Wart Clinic’s surgeons offer a range of removal methods to provide effective and safe relief.