Warts in children

Warts are small benign skin lesions caused by certain types of the human papillomavirus (HPV) that infect the skin surface.

They are especially frequent during school age. They can appear on any part of the body, although they are more usual on the hands, the fingers, the knees, the elbows, the soles of the feet and the face.

They are not cancerous lesions. In most children they disappear spontaneously when the immune system recognises and eliminates the virus, although this process can last months or even a few years.

Warts appear when the virus penetrates the skin through small wounds, cracks or irritated areas. Contagion can occur through:

• Direct contact with a wart.
• Contact with contaminated surfaces.
• Shared use of towels, files, socks or footwear.
• Scratching or manipulating a lesion.
• Biting the nails or tearing the skin of the fingers.

The virus is transmitted more easily when the skin is moist or damaged. Some children present a greater predisposition, especially those with atopic dermatitis, abundant sweating, a habit of biting their nails or diminished immune defences.

The appearance of warts is not related to poor hygiene.

The appearance of warts varies according to their location.

Common warts. They usually appear on the hands, the fingers, the elbows or the knees. They present as hard and raised lesions, with a rough surface, a colour similar to that of the skin and small dark dots inside. These black dots are not roots: they correspond to small thrombosed blood vessels.

Plantar warts. They appear on the soles of the feet. Due to the pressure when walking, they grow inwards, may be covered by a hard layer of skin and can cause pain, as if the child were stepping on a small stone. Sometimes they appear grouped forming a mosaic wart.

Flat warts. They are small, smooth, slightly raised and skin-coloured, yellowish or slightly brown. Numerous lesions usually appear on the face, the back of the hands and the legs.

Filiform warts. They are thin and elongated lesions that appear mainly around the lips, the nose and the eyelids.

The diagnosis is usually made by examination of the skin. The paediatrician or the doctor specialising in skin health will assess the appearance of the lesion, its texture, its location, the presence of vascular dots and the time of evolution.

Dermatoscopy can help to differentiate a wart from other lesions. In exceptional cases, when the appearance is not usual or there are diagnostic doubts, a biopsy may be necessary.

Not all childhood warts need treatment. In children, approximately half can disappear spontaneously during the first months and the vast majority end up resolving in the following years. Therefore, when the lesions are small, do not hurt and do not spread, observation may be chosen.

Treatment is especially recommended when the wart produces pain, bleeds frequently, spreads rapidly, numerous lesions appear, it interferes with walking, writing or doing sports, it is located on the face, it produces a significant emotional impact or the diagnosis is not clear.

Salicylic acid. It is one of the most used treatments for common and plantar warts. It acts by progressively eliminating the layers of the wart. It is usually recommended to soak the area in warm water, to dry it correctly, to gently file the surface with a file for exclusive use, to apply the product only on the wart and to protect the healthy skin around. The treatment requires perseverance and can be prolonged several weeks. It should not be applied on the face, on the genitals, on inflamed or wounded skin, or without medical supervision in very young children.

Cryotherapy. It consists of freezing the wart with liquid nitrogen. It can be effective, but it can produce pain, blisters, temporary changes in pigmentation and the need for several sessions. It is usually reserved for older children who adequately tolerate the procedure.

Cantharidin. Cantharidin is a substance that is applied on the wart in the consulting room and causes the controlled formation of a blister under the lesion. It can be used in certain children because its initial application is usually little painful, although local discomfort may appear afterwards. It must be applied exclusively by a healthcare professional.

Other treatments. In persistent or difficult cases, curettage, keratolytic treatments on medical prescription, topical retinoids for some flat warts, topical or intralesional immunotherapy and laser in very selected cases may be considered. No treatment guarantees that the wart will disappear with a single application and recurrences may occur.

Prevent the child from scratching or tearing off the warts, keep the nails short, do not cut the warts with scissors or blades, do not share towels, socks, shoes, files or nail clippers, wash your hands after applying a treatment and use a different file for the wart that you do not use on healthy skin.

Cover plantar warts with a waterproof dressing in swimming pools or changing rooms, use flip-flops in showers and communal wet areas, change the socks daily if there are plantar warts and do not allow the child to walk barefoot in public changing rooms.

A child with warts can go to school normally and participate in most activities. It is not usually necessary to isolate them.

You should request a medical assessment if the lesion is on the face, the eyelids or the genitals; if the wart bleeds without having been manipulated; if it changes rapidly in colour or appearance; if it produces a lot of pain; if it hinders walking; if numerous warts appear in a short time; if the lesion does not respond to treatment; if there are doubts about whether it really is a wart; if the child has low defences; or if the skin around presents pus, heat or intense inflammation.

Genital or perianal lesions in a child should always be carefully assessed by a healthcare professional to establish the diagnosis and its possible form of transmission.

• Myth: Warts have deep roots. Fact: No. They develop in the superficial layers of the skin. The visible black dots correspond to small blood vessels.
• Myth: Warts appear from touching toads or frogs. Fact: No. They are caused by cutaneous types of the human papillomavirus.
• Myth: You must tear off the wart to cure it. Fact: Tearing it off can cause bleeding, infection and spread of the virus.
• Myth: All warts must be frozen. Fact: No. Many disappear spontaneously and the treatment must be adapted to the age and to the characteristics of each lesion.
• Myth: A child with warts cannot go to the swimming pool. Fact: They can go, but it is advisable to cover the warts, use flip-flops and not share towels.
• Myth: The HPV vaccine prevents all warts on the hands and feet. Fact: Current vaccines mainly protect against certain types of HPV related to anogenital lesions and some cancers, but not against most of the types that produce common cutaneous warts.

• Childhood warts are benign lesions caused by cutaneous types of HPV.
• They are frequent during school age.
• They are transmitted by direct contact, self-inoculation and contaminated objects.
• Many disappear spontaneously.
• Not all need treatment.
• Salicylic acid and cryotherapy are frequent treatments, but they must be adapted to the age of the child.
• They should not be torn off, cut or burned with home remedies.
• Children can go to school and to the swimming pool by adopting simple measures to reduce contagion.
• Painful, atypical, numerous lesions or those located on the face or genitals should be assessed by a professional.