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Infections and infestations Skin and nail

Warts and verrucae

Last revised in October 2024

Warts are small, rough growths which are caused by certain strains of the human papilloma virus (HPV).

Warts and verrucae: Summary

  • Cutaneous warts are small, rough growths that are caused by infection of keratinocytes with human papillomavirus (HPV). They can appear anywhere on the skin but are commonly seen on the hands and feet.
    • A verruca (also known as a plantar wart) is a wart on the sole of the foot.
  • Cutaneous warts are common and can occur at any age, but are unusual in infants and very young children.
    • Incidence is thought to increase during school years reaching a peak in adolescence and early adulthood before declining in later adulthood.
  • Warts are usually spread by direct skin-to-skin contact, or indirectly via contact with contaminated floors or surfaces (for example in swimming pools or communal washing areas).
  • Warts may clear spontaneously at any time, or persist for years. Prognosis varies from person to person and resolution is usually more rapid in children.
  • Benign warts in immunocompetent people almost never undergo malignant change.
  • Warts are diagnosed from their typical appearance:
    • Common warts are firm and raised with a rough surface that resembles a cauliflower (common on knuckles, knees, and fingers).
    • Periungual warts are common warts around the nails that can be painful and disturb nail growth — nail biting is a risk factor.
    • Plane warts are usually round, flat-topped, and skin-coloured or greyish-yellow (common on the face, backs of hands, and shins).
    • Filiform warts have a finger-like appearance and may have a stalk (more common on the face and neck).
    • Palmar and plantar warts grow on the palms and the soles of the feet (verrucae). They often have central dark dots (thrombosed capillaries) and may be painful.
    • Mosaic warts occur when palmar or plantar warts coalesce into larger plaques on the hands and feet.
  • Although warts can be cosmetically unsightly, they are not harmful, usually do not cause symptoms, and most resolve without treatment.
  • Advice should be offered on reducing the risk of transmission and limiting personal spread of warts. Treatment should be considered if a wart is painful, cosmetically unsightly, persistent, or the person requests treatment.
    • Treatment options for non-facial warts in adults and older children include topical salicylic acid, cryotherapy, or a combination of both (cryotherapy is not recommended for younger children).
  • Warts can generally be managed in primary care, but referral to a dermatologist may be indicated if the person has:
    • An uncertain diagnosis.
    • A facial wart.
    • Multiple recalcitrant warts and compromised immunity.
    • Extensive warts.
    • Persistent warts that are unresponsive to available primary care treatments.

Have I got the right topic?

From age 12 months onwards.

This CKS topic covers the management of cutaneous warts.

This CKS topic does not cover the management of anogenital warts, mucosal warts, and other viral skin infections.

There are separate CKS topics on Herpes simplex - genital, Molluscum contagiosum, and Warts - anogenital.

The target audience for this CKS topic is healthcare professionals working within the NHS in the UK, and providing first contact or primary healthcare.

CKS gratefully acknowledges the contribution of the British Association of Dermatologists in the development of this topic.

How up-to-date is this topic?

Changes

October 2024 — reviewed. A literature search was conducted in September to October 2024 to identify evidence-based guidelines, UK policy, systematic reviews, and key randomized controlled trials published since the last revision of this topic. No major changes to recommendations have been made. 

Previous changes

April 2024 — minor update. Microwave therapy added to the secondary care options. 

February 2020 — reviewed. A literature search was conducted in January 2020 to identify evidence-based guidelines, UK policy, systematic reviews, and key randomized controlled trials published since the last revision of this topic. No major changes to recommendations have been made.

September to December 2014 — reviewed. A literature search was conducted in September 2014 to identify evidence-based guidelines, UK policy, systematic reviews, and key randomised controlled trials published since the last revision of this topic. Changes have been made in this topic in line with the British Association of Dermatologists guidance, British Association of Dermatologists' guidelines for the management of cutaneous warts.

November 2011 — minor update to include the results of a Health Technology Assessment that found no evidence to suggest that cryotherapy was more effective than self-treatment with 50% salicylic acid for the treatment of verrucae.

June 2009 — minor update to the text. References have now been inserted to support the contraindications to cryotherapy. 

February to June 2009 — converted from CKS guidance to CKS topic structure. The evidence-base has been reviewed in detail, and recommendations are more clearly justified and transparently linked to the supporting evidence. There have been no major changes to the recommendations.

June 2008 — minor update to the text regarding the use of salicylic acid during pregnancy. We now state that this may be used during pregnancy.

July–September 2006 — rewritten. Validated in December 2006 and issued in January 2007.

November 2005 — minor technical update.

November 2002 — written. Validated in June 2003 and issued in July 2003.

Update

New evidence

Evidence-based guidelines

No new evidence-based guidelines since 1 October 2024.

HTAs (Health Technology Assessments)

No new HTAs published since 1 October 2024.

Economic appraisals

No new economic appraisals relevant to England since 1 October 2024.

Systematic reviews and meta-analyses

No new systematic reviews or meta-analysis which reach the CKS threshold for inclusion since 1 October 2024.

Primary evidence

No new primary evidence which reaches the CKS threshold for inclusion published since 1 October 2024.

New policies

No new national policies or guidelines since 1 October 2024.

New safety alerts

No new safety alerts since 1 October 2024.

Changes in product availability

No changes in product availability since 1 October 2024.

Goals and outcome measures

Goals

To support primary healthcare professionals to:

  • Make an accurate diagnosis of warts and verrucae.
  • Offer initial management in primary care.
  • Refer where appropriate to secondary care or other specialist services.
  • Provide appropriate advice to patients.

Outcome measures

No outcome measures were found during the review of this topic.

Audit criteria

No audit criteria were found during the review of this topic.

QOF indicators

No QOF indicators were found during the review of this topic.

QIPP - Options for local implementation

No QIPP indicators were found during the review of this topic.

NICE quality standards

No NICE quality standards were found during the review of this topic.

Background information

What is it?

  • Cutaneous warts are small, rough growths caused by infection of keratinocytes with human papillomavirus (HPV). They can appear anywhere on the skin but are commonly seen on the hands and feet.
    • A verruca (also known as a plantar wart) is a wart on the sole of the foot.
  • Cutaneous warts may be classified as:
    • Common wart (Verruca vulgaris).
    • Periungual wart — wart around the fingernails or toenails.
    • Plantar wart — wart on the sole of the foot (Verruca plantaris).
    • Flat wart or plane wart (Verruca plana).
      • Acrokeratosis verruciformis and Epidermodysplasia verruciformis are rare inherited conditions characterised by multiple plane type warts.
    • Filiform wart — wart that presents as a cluster of fine fronds emerging from a narrow pedicle base (digitate or finger-like warts). May have a stalk and are most often found on the face or neck.
    • Anogenital wart — wart around the anus or genital area (Condylomata acuminata). See the CKS topic Warts - anogenital for more information.

[Sterling, 2014; PCDS, 2022; Zhu, 2022; DermNet NZ, 2023]

How common is it?

  • Cutaneous warts are common and can occur at any age, but are unusual in infants and very young children [Kwok, 2012; Sterling, 2014].
    • Incidence is thought to increase during school years reaching a peak in adolescence and early adulthood before declining in later adulthood.
    • An estimated 5–30% of school-age children and young adults have warts.
  • A cross-sectional study of the prevalence of skin disease in adults (n = 12,377) from five European countries (Germany, Italy, the Netherlands, Portugal, and Sweden) identified a lifetime prevalence of warts of 41.3% (95% CI 40.4 to 42.2); 7.3% (95% CI 6.9 to 7.8) of the study population had an active manifestation at the time of interview [Svensson, 2018].

How are warts transmitted?

  • Warts are usually spread by direct skin-to-skin contact, or indirectly via contact with contaminated floors or surfaces (for example from swimming pool or shower room floors).
  • Risk of developing cutaneous warts is increased if:
    • The epithelial barrier is damaged.
      • There are skin conditions causing breaks in the skin.
      • Skin is wet and/or macerated.
      • There is contact with rough surfaces causing microtrauma to the skin.
      • Shaving may spread warts over the beard area.
      • New warts may develop along sites of trauma (Koebner phenomenon).
    • An existing wart is scratched, picked or knocked — common warts on the fingers may spread widely around the nails in people who bite their nails or the skin around the nails (autoinoculation).
    • Occupation involves regular direct handling of meat or fish — associated with a greater risk of hand warts.
    • There is frequent immersion in water (for example swimming or regular dishwashing).
    • The person is immunosuppressed.
  • Human papillomavirus (HPV) can survive for months to years on contaminated surfaces.
  • The incubation period for warts is thought to range from a few weeks to more than a year.

[Witchey, 2018; PCDS, 2022; BMJ Best Practice, 2023; DermNet NZ, 2023] 

What is the prognosis?

  • Warts may clear spontaneously at any time or persist for years. Prognosis varies from person to person and resolution is usually more rapid in children.
    • In children, around a quarter of warts resolve spontaneously within 2-3 months, half clear within a year, two-thirds by 2 years, and 90% within 5 years.
    • Spontaneous resolution in adults tends to be slower, and warts may persist for 5-10 years.
    • The Human papillomavirus (HPV) type may influence the likelihood of spontaneous regression.
  • For people with severe immunosuppression (for example after organ or bone marrow transplant) warts may be large, extensive, and resistant to treatment.

[Bruggink, 2013; Sterling, 2014; Bristow, 2022; BMJ Best Practice, 2023]

What are the complications?

  • Complications may include:
    • Spread caused by picking at the wart.
    • Spread to contacts.
    • Local infection.
    • Changes in skin pigmentation and scarring following destructive treatments.
    • Psychosocial impact - teasing at school, embarrassment, unsightly appearance, or exclusion from swimming lessons.
    • Nail dystrophy and destruction from periungual warts.
    • Pain from extensive plantar warts may interfere with walking or sporting activities and lead to knee or hip pain.
  • Malignant changes are thought to be rare, but have been reported in immunosuppressed people. Lesions may initially have appeared as warts and later transform into squamous cell carcinoma. In epidermodysplasia verruciformis (a rare inherited condition) the human papillomavirus type can cause cutaneous squamous cell carcinomas.

[Kwok, 2012; BMJ Best Practice, 2023; DermNet NZ, 2023]

Diagnosis of warts and verrucae

How should I diagnose warts and verrucae?

  • Warts are diagnosed from their typical appearance.
    • Common warts — firm, raised papules with a rough surface that resembles a cauliflower (common on knuckles, knees, and fingers) — usually asymptomatic but may be tender.
      • Periungual warts are common warts around the nails that can be painful and disturb nail growth — nail biting is a risk factor.
    • Plane warts — usually round, flat-topped, and skin-coloured or greyish-yellow (common on the face, backs of hands, and shins).
    • Filiform warts — finger-like appearance and may have a stalk (more common on the face and neck).
    • Palmar and plantar warts — grow on the palms and the soles of the feet (verrucae). They often have central dark dots (thrombosed capillaries) and may be painful.
    • Mosaic warts — occur when palmar or plantar warts coalesce into larger plaques on the hands and feet.
    • For images of typical appearances, see the DermNet website or that of the Primary Care Dermatology Society.
  • Diagnosis is usually clinical and in most people, further investigations are not required.
    • If there is diagnostic doubt, light paring of a wart will reveal tiny black dots on the surface (thrombosed capillaries) but be aware that bleeding may lead to warts spreading.
    • Examination with a dermatoscope may be helpful when there is diagnostic doubt for those clinicians experienced in the use of this tool.
    • If lesions are atypical referral for specialist assessment should be arranged.

Basis for recommendation

This information is based on expert opinion from The British Association of Dermatologists' guidelines for the management of cutaneous warts [Sterling, 2014], the Primary Care Dermatology Society web page entitled Warts [PCDS, 2022], the British Medical Journal (BMJ) Best Practice guide Common warts [BMJ Best Practice, 2023],  the Chinese Clinical guideline for the diagnosis and treatment of cutaneous warts (2022) [Zhu, 2022], and review articles Plantar warts: Epidemiology, pathophysiology and clinical management [Witchey, 2018], Paediatric cutaneous warts and verrucae: an update [Bristow, 2022], and Plantar verruca and dermoscopy: An update [Bhatti, 2021].

What else might it be?

  • Differential diagnoses of warts include:
    • Molluscum contagiosum. Umbilicated pinkish or pearly white smooth papules that usually occur in clusters. See the CKS topic Molluscum contagiosum for more information.
    • Corns or calluses on the feet. These may appear together with plantar warts. Calluses occur over areas of friction or pressure, have a smooth surface with intact skin markings, and black dots/bleeding points are not seen on paring.
    • Actinic keratosis. Pre-cancerous lesions that appear as white or yellow flat or thickened papules or plaques, usually on sun-exposed areas.
    • Bowen’s disease. Non-healing, enlarging hyperkeratotic papules that become inflamed and tender.
    • Seborrheic keratosis. Lesions are variable in appearance but often grey-brown scaly plaques or papules that may have a smooth or rough surface, appearing as if stuck onto the skin surface.
    • Knuckle pads. Thickened areas over finger joints.
    • Squamous cell carcinoma. Enlarging, non-healing hyperkeratotic papules that become inflamed and tender.
    • Focal palmoplantar keratoderma. Thickened areas affecting the epidermis of pressure areas of the soles of the feet or palms of the hands
    • Lichen planus. Usually a widespread, itchy rash.
    • Angiokeratoma. Asymptomatic blue-red papules that may occur anywhere on the skin, usually measuring less than 5 mm in diameter.
    • Malignant melanoma. Lesions typically have an irregular outline and colour, and may itch or bleed. See the CKS topic Melanoma for more information.

Basis for recommendation

The information is based on the British Medical Journal (BMJ) Best Practice guide Common warts [BMJ Best Practice, 2023], the DermNet topic Viral wart [DermNet NZ, 2023], and The British Association of Dermatologists' guidelines for the management of cutaneous warts [Sterling, 2014].

Management

Scenario: Management

From age 12 months onwards.

Should warts and verrucae be treated?

  • For most people there is a strong case for not treating warts or verrucae.
    • Cutaneous warts do not usually cause symptoms and in most cases resolve spontaneously. 
    • This is particularly an option to consider in children, for whom warts are more likely to resolve spontaneously and treatment may be uncomfortable or not tolerated.
    • Treatment may be prolonged and can have adverse effects.
      • Cryotherapy requires several treatments, can be painful at the time of application, and may cause pain, blistering, infection, scarring, and depigmentation.
      • Topical salicylic acid may require administration for up to 12 weeks and can cause local skin irritation.
  • Consider treatment if:
    • The wart is painful (for example on the soles of the feet or near the nails).
    • The wart is cosmetically unsightly (for example on the hands or face).
    • The person requests treatment and the wart is persisting.
  • Provide general advice to all people presenting with warts or verrucae, whether treating or not. Advise them to return for review if the symptoms change or worsen and a decision has been made not to treat.

Basis for recommendation

These recommendations are based on The British Association of Dermatologists' guidelines for the management of cutaneous warts [Sterling, 2014], the British Medical Journal (BMJ) best practice guide Common warts [BMJ Best Practice, 2023], a Cochrane review Topical treatments for cutaneous warts [Kwok, 2012], and information on the website of the Primary Care Dermatology Society on Warts [PCDS, 2022].

  • Give general advice, and provide patient information on warts and verrucae, for example, from the Primary Care Dermatology Society or the NHS.
  • Facial warts should not routinely be treated in primary care — refer to dermatology if treatment is indicated.
  • For non-facial warts:
    • For adults and older children, treatment depends upon what has been tried already and what the person prefers. Options include:
      • Topical salicylic acid (most available preparations are 12–26 %) applied daily for up to 12 weeks. For more information see the section on Topical salicylic acid. Usually, advice to purchase these preparations over the counter is appropriate under NHS England's prescribing policy for conditions for which over the counter items should not be routinely prescribed in primary care.
      • Cryotherapy with liquid nitrogen (usually carried out every 2–4 weeks until the wart is gone, up to a maximum of six treatments). Note: cryotherapy is only suitable for some older children who are likely to tolerate this treatment. For more information, see the section on Cryotherapy.
      • Combination therapy with salicylic acid and cryotherapy (applying topical salicylic acid preparations between cryotherapy sessions once the scabbing from cryotherapy has resolved).
      • A shorter cryotherapy freeze (for example 5–10 seconds) or a weaker strength topical salicylic acid preparation (for example 17% or less) is recommended for plane warts on the back of the hands, as scarring is more likely to occur.
      • Plantar warts are difficult to treat and cryotherapy is less likely to help — as pain caused by plantar warts is usually due to thickening of the skin regular paring can help make the feet more comfortable. Care should be taken when paring to avoid abrading the surrounding normal skin, as this may lead to spread. Combination therapy and more aggressive cryotherapy regimens may be helpful.
    • For younger children, where treatment is wanted, recommend treatment with topical salicylic acid applied daily for up to 12 weeks.

Basis for recommendation

These recommendations are based largely on the British Association of Dermatologists (BAD) British Association of Dermatologists' guidelines for the management of cutaneous warts [Sterling, 2014], as well as information from the Primary Care Dermatological Society (PCDS) on Warts [PCDS, 2022], the British Medical Journal (BMJ) Best practice guide Common warts [BMJ Best Practice, 2023], a Cochrane review on Topical treatments for cutaneous warts [Kwok, 2012], the NHS England Policy guidance: conditions for which over the counter items should not be routinely prescribed in primary care [NHSE, 2024], the British National Formulary (BNF) [BNF, 2024], the Electronic Medicines Compendium (emc) [EMC, 2024a], and expert opinion and a review of the recent evidence in the review article Paediatric cutaneous warts and verrucae: an update [Bristow, 2022].

When should I refer someone with warts or verrucae?

  • In general, most warts can be managed in primary care. Specialized treatments may be available in secondary care depending on local referral guidelines.
  • Consider referral to a dermatologist, if:
    • The person has a facial wart.
    • The diagnosis is uncertain.
    • The person is immunocompromised.
    • The person has areas of skin that are extensively affected, for example, mosaic warts of the hands and feet.
    • The person is troubled by symptoms from persistent warts which are unresponsive to both topical salicylic acid and cryotherapy. 

Treatment options in secondary care

  • Treatment options in secondary care may include:
    • Physical ablation, such as surgery, laser, microwave, and photodynamic treatment.
    • Antimitotic treatments, such as topical podophyllin, topical or oral retinoids, or intralesional bleomycin.
    • Immunomodulatory treatments, such as topical sensitizers (such as diphenylcyclopropenone or squaric acid dibutyl ester),or topical imiquimod 5%. Other intralesional immunotherapy agents studied include candida antigen, tuberculin antigens, the measles, mumps and rubella vaccine, and interferon.
    • Virucidal treatments, such as formaldehyde and glutaraldehyde.
    • Topical chemotherapy agents such as 5-fluorouracil.
    • Cantharidin (a potent blistering agent extracted from blister beetles). This has been studied in a formulation which also includes podophyllotoxin and salicylic acid.

Basis for recommendation

Referral criteria will ultimately depend upon local referral guidance. Exceptional funding requests may be required. The suggested indications for referral are based on expert opinion in the British Association of Dermatologists' (BAD) guidelines for the management of cutaneous warts 2014 [Sterling, 2014], information from the Primary Care Dermatology Society on Warts [PCDS, 2022], and a UK-based review article Management of cutaneous viral warts [Lynch, 2014].

The information on possible treatment options in secondary care is based on the sources above as well as the British Medical Journal (BMJ) best practice guide Common warts [BMJ Best Practice, 2023], information from DermNet on Viral wart [DermNet NZ, 2023], and expert opinion in review articles Paediatric cutaneous warts and verrucae: an update [Bristow, 2022], Systematic review of intralesional therapies for cutaneous warts [Mullen, 2024] and Topical treatment for plantar warts: A systematic review [García-Oreja, 2021].

What advice should I give to someone with warts or verrucae?

  • Advise that:
    • Although warts can be cosmetically unsightly, they are not harmful; usually, they do not cause symptoms and resolve without treatment.
    • Warts are contagious, but the risk of transmission is thought to be low.
    • To reduce the risk of transmission:
      • Cover the wart with a waterproof plaster when swimming. Organisations such as Aquatics GB and Swim England state that the use of swimming socks should be discouraged and that a waterproof plaster is sufficient.
      • Avoid going barefoot in public places. Wear flip-flops or other appropriate footwear in communal showers.
      • Avoid sharing shoes, socks, or towels.
    • To limit personal spread (auto-inoculation):
      • Avoid picking or scratching lesions.
      • Avoid biting nails or sucking fingers that have warts.
      • Keep feet dry and change socks or tights daily.
      • When treating the wart, dispose of any skin filings hygienically, and do not use the emery board or pumice stone for anything else.
    • Children with warts or verrucae should not be excluded from activities, such as sports and swimming, but should take care to minimize transmission.
    • Provide patient information, such as:

Basis for recommendation

These recommendations are based on expert advice from the Primary Care Dermatology Society on Warts [PCDS, 2022], a patient information leaflet published by the British Association of Dermatologists, Plantar warts (verrucas) [BAD, 2022a], and the British Medical Journal (BMJ) best practice guide Common warts [BMJ Best Practice, 2023], as well as on information on the website for Aquatics GB, Understanding verrucas [Aquatics GB, 2024] and the website for Swim England, Swimming and verrucas, the facts [Swim England, 2024].

Prescribing information

Important aspects of prescribing information relevant to primary healthcare are covered in this section specifically for the drugs recommended in this CKS topic. For further information on contraindications, cautions, drug interactions, and adverse effects, see the electronic Medicines Compendium (eMC) or the British National Formulary (BNF).

Topical salicylic acid

Which topical salicylic acid preparations are available?

  • Many preparations containing topical salicylic acid are available over the counter or to prescribe in the UK, examples include:
    • Duofilm® (salicylic acid 16.7% plus lactic acid 15%) — licensed for warts.
    • Bazuka® gel (salicylic acid 12% plus lactic acid 4%) and Bazuka® extra strength gel (salicylic acid 26%) — licensed for warts, verrucae, corns, and calluses.
    • Occlusal® (salicylic acid 26%) — licensed for common and plantar warts.
    • Salactol® (salicylic acid 16.7% plus lactic acid 16.7%) — licensed for warts, verrucae, corns, and calluses.
    • Salatac® gel (salicylic acid 12% plus lactic acid 4%) — licensed for warts, verrucae, corns, and calluses.

[Sterling, 2014; BNF, 2024; EMC, 2015; EMC, 2016; EMC, 2024b; EMC, 2024c; EMC, 2024d; NHSE, 2024]

Who should not receive topical salicylic acid?

  • Topical salicylic acid should not be used on:
    • The face.
    • Intertriginous or anogenital regions.
    • Moles or birthmarks.
    • Mucous membranes.
    • Warts with hair growing out of them, red edges, or an unusual colour.
    • Open wounds, irritated or reddened skin, or any area that is infected.
    • Areas of poor healing, such as neuropathic feet, or in those with impaired blood circulation, such as people with diabetes.
    • Large areas of skin.
    • Children under the age of 2 years.
  • Avoid applying to normal skin.
  • For some products the manufacturers recommend avoidance of use in pregnancy and lactation. Most note that although there are no known issues, safety has not been established during pregnancy and lactation.

[Sterling, 2014; BNF, 2024; EMC, 2015; EMC, 2016; EMC, 2024b; EMC, 2024c; EMC, 2024d]

How should topical salicylic acid be applied?

  • Application instructions may vary; consult individual product literature. In general, application is as follows:
    • Apply once a day, at night.
    • Before applying, soak the affected area in warm water for 2–5 minutes, then dry thoroughly with a towel not used for any other area or person. Some products then advise gently debriding the surface of the wart or verruca with an emery board or pumice stone — excess abrasion may enhance the spread of the virus to surrounding skin. The salicylic acid product is then applied directly on the wart, taking care to avoid the surrounding normal skin.
    • For subsequent applications, peel off any film remaining from the previous application and debride and soak as above.
    • Avoid applying the treatment to the surrounding skin by applying carefully to the wart and protecting the surrounding skin with soft paraffin or plaster.
    • Do not apply to the face or areas that are extensively affected because of an increased risk of skin irritation and scarring.

[Sterling, 2014; BNF, 2024; EMC, 2015; EMC, 2016; EMC, 2024b; EMC, 2024c; EMC, 2024d]

What are the adverse effects of topical salicylic acid?

  • Topical salicylic acid therapy may cause irritation of the skin, which may include rash, itch, burning sensation, redness, scaling, or dryness.
  • Rarely, it may cause skin discolouration at the application site, blistering, allergic dermatitis, and skin exfoliation.

[Sterling, 2014; BNF, 2024; EMC, 2015; EMC, 2016; EMC, 2024b; EMC, 2024c; EMC, 2024d]

Cryotherapy

Who should not receive topical cryotherapy?

Only practitioners who have been trained in the use of cryotherapy should carry out this treatment.

  • Avoid using cryotherapy in the following circumstances:
    • People with an uncertain diagnosis or a possible malignancy.
    • Young children (who may find it too painful).
    • People who have had a previous adverse reaction to cryotherapy.
    • People with darker skin due to the risk of pigment changes.
    • Hair-bearing skin.
    • Distal extremities in people with:
      • Raynaud's syndrome.
      • Peripheral vascular disease.
      • Peripheral neuropathy.
    • Lower legs in elderly people.
    • Periungual sites — this is painful and there is a risk of subungual haemorrhage and nail deformity.
    • Eyelids and nasal folds.
    • People with autoimmune and underlying haematological disease.
  • For warts over tendons or near superficial nerves it is preferable to use topical salicylic acid. Cryotherapy may be considered but with shorter durations of freeze-thaw cycles.

[Sterling, 2014; PCDS, 2022; PCDS, 2024]

How should cryotherapy be applied?

Only practitioners who have been trained in the use of cryotherapy should carry out this treatment.

  • Before performing cryotherapy, obtain informed consent and document when cryotherapy is undertaken and the thaw and freeze times used.
  • If treating a plantar wart (but not a hand wart), pare down the dead skin before applying cryotherapy.
  • A spray is commonly used to apply liquid nitrogen. The nozzle is held 1–1.5 cm away from the wart being treated. The spray is applied until a 2 mm halo of frozen tissue appears around the wart, and is then timed for 5–30 seconds (for example 5–10 seconds in children, 10–15 seconds on the fingers in adults) depending on the site and size of the wart. Two freeze-thaw cycles are usually needed at each treatment of warts (The lesion is kept frozen by pulses of spray for the desired freeze time, then allowed to thaw and repeated).
  • Standard practice is to repeat this treatment every 3–4 weeks until the wart has gone, up to a maximum of six treatments.
  • The Primary Care Dermatology Society provides information on cryotherapy including a video of the technique and consent form.

[Sterling, 2014; DermNet NZ, 2022; PCDS, 2024]

What are the adverse effects of cryotherapy?

  • Cryotherapy may cause:
    • Pain — pain may occur, but cryotherapy is usually well tolerated.
    • Blistering — this usually settles after a few days as a scab forms.
    • Swelling and redness — this usually settles after 2–3 days.
    • Scarring (rare).
    • Leg ulceration.
    • Hypo- or hyperpigmentation, particularly in dark skin — this usually improves with time but it may be permanent.
    • Numbness may occur if a superficial nerve is frozen. Normal feeling usually returns within a few months.
    • Secondary infection.
    • Tendon or nerve damage especially with treatment to warts on the fingers.
    • Onychodystrophy (malformation of the nails) following treatment of periungual warts.

[Sterling, 2014; BAD, 2022b; DermNet NZ, 2022; BMJ Best Practice, 2023; PCDS, 2024]

Supporting evidence

This CKS topic is largely based on the clinical guideline British Association of Dermatologists' guidelines for the management of cutaneous warts [Sterling, 2014], information on Warts from the Primary Care Dermatology Society [PCDS, 2022], the British Medical Journal (BMJ) Best Practice guide Common warts [BMJ Best Practice, 2023] and expert opinion in review articles.  The rationale for the individual recommendations for primary care assessment and management of warts and verrucae is outlined in the relevant basis for recommendation sections of the topic. 

How this topic was developed

This section briefly describes the processes used in developing and updating this topic. Further details on the full process can be found in the About Us section and on the Clarity Informatics website.

Search strategy

A literature search was conducted for guideline and systematic reviews on primary care management of warts and verrucae.

Search dates

December 2019 - September 2024

Key search terms

The terms listed below are the core search terms that were used for EBSCOhost MEDLINE (searched 9th December 2019). These were combined with filters to identify guidelines, systematic reviews and primary care relevant literature in EBSCOhost MEDLINE. The strategy was adapted for The Cochrane Library databases. 

S3    S1 OR S2 
S2    AB ( wart or warts or verruca* ) OR TI ( wart or warts or verruca* ) 
S1    (MH "Warts") 

Sources of guidelines

Sources of systematic reviews and meta-analyses

  • The Cochrane Library:
    • Systematic reviews
    • Protocols
    • Database of Abstracts of Reviews of Effects
  • Medline (with systematic review filter)
  • EMBASE (with systematic review filter)

Sources of health technology assessments and economic appraisals

Sources of randomized controlled trials

  • The Cochrane Library:
    • Central Register of Controlled Trials
  • Medline (with randomized controlled trial filter)
  • EMBASE (with randomized controlled trial filter)

Sources of evidence based reviews and evidence summaries

Sources of national policy

Patient experiences

Sources of medicines information

The following sources are used by CKS pharmacists and are not necessarily searched by CKS information specialists for all topics. Some of these resources are not freely available and require subscriptions to access content.

Stakeholder engagement

Our policy

The external review process is an essential part of CKS topic development. Consultation with a wide range of stakeholders provides quality assurance of the topic in terms of:

  • Clinical accuracy.
  • Consistency with other providers of clinical knowledge for primary care.
  • Accuracy of implementation of national guidance (in particular NICE guidelines).
  • Usability.

Principles of the consultation process

  • The process is inclusive and any individual may participate.
  • To participate, an individual must declare whether they have any competing interests or not. If they do not declare whether or not they have competing interests, their comments will not be considered.
  • Comments received after the deadline will be considered, but they may not be acted upon before the clinical topic is issued onto the website.
  • Comments are accepted in any format that is convenient to the reviewer, although an electronic format is encouraged.
  • External reviewers are not paid for commenting on the draft topics.
  • Discussion with an individual or an organization about the CKS response to their comments is only undertaken in exceptional circumstances (at the discretion of the Clinical Editor or Editorial Steering Group).
  • All reviewers are thanked and offered a letter acknowledging their contribution for the purposes of appraisal/revalidation.
  • All reviewers are invited to be acknowledged on the website. All reviewers are given the opportunity to feedback about the external review process, enabling improvements to be made where appropriate.

Stakeholders

  • Key stakeholders identified by the CKS team are invited to comment on draft CKS topics. Individuals and organizations can also register an interest to feedback on a specific topic, or topics in a particular clinical area, through the Getting involved section of the Clarity Informatics website.
  • Stakeholders identified from the following groups are invited to review draft topics:
    • Experts in the topic area.
    • Professional organizations and societies (for example, Royal Colleges).
    • Patient organizations, Clarity has established close links with groups such as Age UK and the Alzheimer’s Society specifically for their input into new topic development, review of current topic content and advice on relevant areas of expert knowledge.
    • Guideline development groups where the topic is an implementation of a guideline.
    • The British National Formulary team.
    • The editorial team that develop MeReC Publications.
  • Reviewers are provided with clear instructions about what to review, what comments are particularly helpful, how to submit comments, and declaring interests.

Patient engagement

Clarity Informatics has enlisted the support and involvement of patients and lay persons at all stages in the process of creating the content which include:

  • Topic selection
  • Scoping of topic
  • Selection of clinical scenarios
  • First draft internal review
  • Second draft internal review
  • External review
  • Final draft and pre-publication

Our lay and patient involvement includes membership on the editorial steering group, contacting expert patient groups, organizations and individuals.

Evidence exclusion criteria

Our policy

Scoping a literature search, and reviewing the evidence for CKS is a methodical and systematic process that is carried out by the lead clinical author for each topic. Relevant evidence is gathered in order that the clinical author can make fully informed decisions and recommendations. It is important to note that some evidence may be excluded for a variety of reasons. These reasons may be applied across all CKS topics or may be specific to a given topic.

Studies identified during literature searches are reviewed to identify the most appropriate information to author a CKS topic, ensuring any recommendations are based on the best evidence. We use the principles of the GRADE and PICOT approaches to assess the quality of published research. We use the principles of AGREE II to assess the quality of published guidelines.

Standard exclusions for scoping literature:

  • Animal studies
  • Original research is not written in English

Possible exclusions for reviewed literature:

  • Sample size too small or study underpowered
  • Bias evident or promotional literature
  • Population not relevant
  • Intervention/treatment not relevant
  • Outcomes not relevant
  • Outcomes have no clear evidence of clinical effectiveness
  • Setting not relevant
  • Not relevant to UK
  • Incorrect study type
  • Review article
  • Duplicate reference

Organizational, behavioural and financial barriers

Our policy

The CKS literature searches take into consideration the following concepts, which are discussed at the initial scoping of the topic.

  • Feasibility
    • Studies are selected depending on whether the intervention under investigation is available in the NHS and can be practically and safely undertaken in primary care.
  • Organizational and Financial Impact Analysis
  • Studies are selected and evaluated on whether the intervention under investigations may have an impact on local clinical service provision or national impact on cost for the NHS. The principles of clinical budget impact analysis are adhered to, evaluated and recorded by the author. The following factors are considered when making this assessment and analysis.
    • Eligible population
    • Current interventions
    • Likely uptake of new intervention or recommendation
    • Cost of the current or new intervention mix
    • Impact on other costs
    • Condition-related costs
    • In-direct costs and service impacts
    • Time dependencies
  • Cost-effectiveness or cost-benefit analysis studies are identified where available. 

We also evaluate and include evidence from NICE accredited sources which provide economic evaluations of recommendations, such as NICE guidelines. When a recommended action may not be possible because of resource constraints, this is explicitly indicated to healthcare professionals by the wording of the CKS recommendation.

Declarations of interest

Our policy

Clarity Informatics requests that all those involved in the writing and reviewing of topics, and those involved in the external review process to declare any competing interests. Signed copies are securely held by Clarity Informatics and are available on request with the permission of the individual. A copy of the declaration of interest form which participants are asked to complete annually is also available on request. A brief outline of the declarations of interest policy is described here and full details of the policy is available on the Clarity Informatics website. Declarations of interests of the authors are not routinely published, however competing interests of all those involved in the topic update or development are listed below. Competing interests include:

  • Personal financial interests
  • Personal family interest
  • Personal non-financial interest
  • Non-personal financial gain or benefit

Although particular attention is given to interests that could result in financial gains or losses for the individual, competing interests may also arise from academic competition or for political, personal, religious, and reputational reasons. An individual is not obliged to seek out knowledge of work done for, or on behalf of, the healthcare industry within the departments for which they are responsible if they would not normally expect to be informed.

Who should declare competing interests?

Any individual (or organization) involved in developing, reviewing, or commenting on clinical content, particularly the recommendations should declare competing interests. This includes the authoring team members, expert advisers, external reviewers of draft topics, individuals providing feedback on published topics, and Editorial Steering Group members. Declarations of interest are completed annually for authoring team and editorial steering group members, and are completed at the start of the topic update and development process for external stakeholders.

Competing interests declared for this topic:

None.

References

  • Aquatics GB (2024) Understanding verrucas. British Swimming. https://www.britishswimming.org [Free Full-text]
  • BAD (2022a) Plantar warts. Patient Information Leaflet (PIL). British Association of Dermatologists. https://www.bad.org.uk [Free Full-text]
  • BAD (2022b) Cryotherapy. Patient Information Leaflet (PIL). British Association of Dermatologists. https://www.bad.org.uk [Free Full-text]
  • Bhatti, A., Chodhary, S., Ferrise, T., et al. (2021) Plantar verruca and dermoscopy: an update. Clinics in Podiatric Medicine and Surgery 38(4), 513-520. [Abstract]
  • BMJ Best Practice (2023) Common warts. BMJ Publishing Group. https://bestpractice.bmj.com
  • BNF (2024) British National Formulary. National Institute for Health and Care Excellence. https://bnf.nice.org.uk
  • Bristow, I. (2022) Paediatric cutaneous warts and verrucae: an update. Environmental Research and Public Health 19(24), 16400. [Abstract] [Free Full-text]
  • Bruggink, S., Eekhof, J., Egberts, P., et al. (2013) Natural course of cutaneous warts among primary schoolchildren: a prospective cohort study. Annals of Family Medicine 11(5), 437-441. [Abstract]
  • DermNet NZ (2022) Cryotherapy. DermNet. https://dermnetnz.org [Free Full-text]
  • DermNet NZ (2023) Viral wart. DermNet. https://dermnetnz.org [Free Full-text]
  • EMC (2015) SPC for Occlusal. Electronic Medicines Compendium. Datapharm Communications Ltd. https://www.medicines.org.uk/emc [Free Full-text]
  • EMC (2016) SPC for Duofilm. Electronic Medicines Compendium. Datapharm Communications Ltd. https://www.medicines.org.uk/emc [Free Full-text]
  • EMC (2024a) Electronic Medicines Compendium: Home. Datapharm Communications Ltd. https://www.medicines.org.uk/emc [Free Full-text]
  • EMC (2024b) SPC for Bazuka Treatment Gel. Electronic Medicines Compendium. Datapharm Communications Ltd. https://www.medicines.org.uk/emc [Free Full-text]
  • EMC (2024c) SPC for Salactol Collodion. Electronic Medicines Compendium. Datapharm Communications Ltd. https://www.medicines.org.uk/emc [Free Full-text]
  • EMC (2024d) SPC for Salatac Gel. Electronic Medicines Compendium. Datapharm Communications Ltd. https://www.medicines.org.uk/emc [Free Full-text]
  • García-Oreja, S., Álvaro-Afonso, F. J., García-Álvarez, Y., et al. (2021) Topical treatment for plantar warts: A systematic review. Dermatologic Therapy 34(1), e14621. [Abstract]
  • Kwok, C.S., Gibbs, S., Bennett, C., et al. (2012) Topical treatments for cutaneous warts (Cochrane Review). The Cochrane Library. John Wiley & Sons, Ltd. http://www.cochranelibrary.com [Free Full-text]
  • Lynch, M., Cliffe, J. and Morris-Jones, R. (2014) Management of cutaneous viral warts. British Medical Journal 348, g3339. [Abstract]
  • Mullen, S.A., Myers, E.L., Brenner, R.L., et al. (2024) Systematic review of intralesional therapies for cutaneous warts. Journal of Investigative Dermatology (JID) Innovations 4(3), 100264. [Abstract] [Free Full-text]
  • NHS England (2024) Policy guidance: conditions for which over the counter items should not be routinely prescribed in primary care. NHS England. https://www.england.nhs.uk [Free Full-text]
  • PCDS (2022) Warts. Primary Care Dermatology Society. https://www.pcds.org.uk [Free Full-text]
  • PCDS (2024) Cryotherapy (also known as cryosurgery). Primary Care Dermatology Society. https://www.pcds.org.uk [Free Full-text]
  • Sterling, J.C., Gibbs, S., Haque Hussain, S.S., et al. (2014) British Association of Dermatologists' guidelines for the management of cutaneous warts 2014. British Journal of Dermatology 171(4), 696-712. [Abstract]
  • Svensson, A., Ofenloch, R.F., Bruze, M., et al. (2018) Prevalence of skin disease in a population-based sample of adults from five European countries. British Journal of Dermatology 178(5), 1111-1118. [Abstract]
  • Swim England (2024) Swimming and verrucas, the facts. Swim England. https://www.swimming.org [Free Full-text]
  • Witchey, D.J., Witchey, N.B., Roth-Kauffman, M.M. and Kauffman, M.K. (2018) Plantar warts: Epidemiology, pathophysiology, and clinical management. Journal of Osteopathic Medicine 118(2), 92-105. [Abstract] [Free Full-text]
  • Zhu, P., Qi, R.Q., Yang, Y., et al. (2022) Clinical guideline for the diagnosis and treatment of cutaneous warts (2022). Journal of Evidence Based Medicine 15(3), 284-301. [Abstract] [Free Full-text]
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