Warts: causes, spread and removal

Key takeaways

• Warts are caused by HPV, a virus with many types. Common, flat, plantar (sole) and filiform warts look different and are treated differently.
• They spread by direct contact and by self-spread from scratching, shaving, threading or picking, which can create lines of new warts.
• Without treatment, about half of children's warts clear within six months and about 90 percent within two years. Adults' warts tend to persist longer.
• Treatments include salicylic acid, liquid nitrogen freezing, cautery, laser and immune treatments. None kills the virus directly, so patience and repeat sessions are common.
• Warts on the face or genitals, or warts that bleed, change or keep coming back, should be seen by a doctor.

What causes warts?

Warts are caused by the human papillomavirus, HPV. DermNet notes there are more than 150 types, and only some affect the skin. The virus gets into the top layer of skin through a small cut or break, and makes the cells there grow faster, forming a rough bump.

The incubation period can be long, up to a year according to DermNet. That is why people are often puzzled: "Doctor, where did I get this from?" Normally, there is no way to know.

What types of warts are there?

On Indian skin, flat warts are often brown rather than skin-coloured, so people mistake them for pigmentation or small moles.

How do warts spread?

See, what happens is, the virus moves from the wart to nearby skin whenever that skin gets a tiny break. DermNet describes spread by direct contact and by autoinoculation, which means spreading it to yourself through scratching or picking. This can produce lines of warts along a scratch.

Some common ways I see warts spread in my clinic: - Shaving. Men with flat warts on the beard area often spread them along the cheeks with a razor. DermNet notes shaving can spread plane warts. - Threading. Indian case reports describe warts and molluscum, another skin virus, spreading along the eyebrows after parlour threading. - Biting nails or picking at warts on the fingers. - Walking barefoot in shared bathrooms, gyms and swimming pools, for verrucas. - Sharing towels, razors and footwear.

The NHS advises not sharing towels, socks or shoes, not biting nails or sucking fingers with warts, not walking barefoot in public places with a verruca, and not scratching or picking a wart.

Do warts go away on their own?

Many do. DermNet notes that without treatment, about 50 percent of children's warts disappear within six months and about 90 percent within two years. In adults, warts tend to last longer, and they recur more often in smokers and in people with a weak immune system.

So for a single small wart that does not bother you, waiting is a reasonable choice. That is your call. But on the face, on the beard area, near the nails, or if they are multiplying, I would treat them, because each new wart is another source of spread.

How are warts treated?

DermNet makes one point I always repeat to patients: treatments do not kill the virus. They destroy the wart tissue or help the immune system recognise it. That is why warts can come back and why more than one session is common.

The success figures above are from DermNet's summary. Results vary, and some warts need a combination.

For flat warts on the face, I am very careful. Strong acids and aggressive freezing can leave white or dark marks on brown skin, which may be more noticeable than the wart. Gentle cautery or carefully chosen creams, with sunscreen afterwards, usually suit the face better. DermNet notes that a hard freeze may leave a lasting white mark and that electrosurgery leaves a scar, so I choose the method by site and skin type.

What should I do and avoid while I have warts?

• Do not pick, scratch or bite them.
• Do not shave over flat warts on the face. Use a trimmer, or shave around them, until they are treated.
• Do not thread or wax over warts on the eyebrows or upper lip.
• Cover warts on the fingers with a plaster if you work with your hands.
• Wear slippers in shared bathrooms and at the pool.
• Do not use a pumice stone or file on a wart and then on other skin.
• Do not use acid wart paints on the face or genitals.

When should a wart be checked?

The NHS suggests seeing a doctor if you are worried about a skin growth, if a wart keeps coming back, is very large or painful, bleeds or changes in appearance, or is on the face or genitals. Genital warts are a different matter and should be seen at a sexual health clinic.

Also, not everything that looks like a wart is one. Skin tags, seborrhoeic keratoses, moles and occasionally skin cancers can look similar. DermNet even notes that a pale melanoma on the sole can mimic a wart or callus. If a "wart" on your foot is changing, dark or bleeding, get it checked. See moles: when to get one checked and skin tags.

How we approach this at Dr Tvacha

Removal of unwanted growths, including warts and skin tags, is part of our skin services. At a Rs 499 skin consultation I confirm the diagnosis, check how far the warts have spread, and choose a method suited to the site and your skin tone. You get the method, number of likely sessions and fee in writing before treatment. Basically, I would rather plan two gentle sessions than leave a mark on your face. The approach is on the Second Layer Skin Plan page, and our centres are in Thane, Andheri, Bandra and Dahisar.

Written by

Dr Amit KarkhanisAesthetic Physician · MBBS, Dip. Dermatology (UK) · Reg. No. 2001/02/1124

Founder of Dr Tvacha, practising in Thane since 2005. Leads the weight loss and hair programmes.