management

Last edited 11/2018

Typically warts are benign infections that may persist for months, or even years, and then finally spontaneously resolve.

• if the affected individual is immunocompetent, then an expectant approach to management is entirely acceptable (1)

Prevention

• warts are contagious but the risk of transmission is low
• children with warts should NOT be excluded from physical activities, but should take care to minimise transmission:
• cover the wart with a waterproof plaster when swimming
• wear flip-flops in communal showers
• avoid sharing shoes, socks and towels
• limit personal spread by:
• avoiding scratching lesions
• avoiding biting nails or sucking fingers that have warts
• keeping feet dry and changing socks daily (2)

If the lesions are uncomfortable or interfere with function, or may be a major cosmetic bother and embarrassment (e.g. - when numerous or on sites such as the face) the following treatment modalities may be used:

• topical treatment – intention is to physically or chemically ablate warts and to stimulate an immune response
• salicylic acid (SA)
• are the most common preparation used in the treatment of viral warts
• SA paints 
• most commonly used, over-the-counter product
• contain SA at concentrations of between 10% and 26% in either a collodion or a polyacrylic base
• it is recommended that lesions should be abraded or pared down and/or soaked prior to application. Care should be taken when paring to avoid abrading the surrounding normal skin, as this may spread the disease
• plasters – contains 40% SA
• ointments – contains 60% SA
• at high concentrations it is an irritant and is thought to work by promoting exfoliation of epidermal cells
• additionally, these effects may activate host immunity an induce an immune response against warts
• patients should receive clear instruction on use since compliance is important
• suitable for any cutaneous site except the face
• optimum duration of treatment is unknown, at first instance, 12 weeks of treatment should be considered before considering other types of treatmnet 
• cryotherapy
• liquid nitrogen, delivered by cryospray or cotton bud, is the most commonly used method
• usually carried out in the secondary care or specialist community clinics  due to the difficulty in obtaining and storing liquid nitrogen in a primary care setting
• over the counter products (e.g. - dimethyl ether and propane) may be used for “freezing” warts, not effective when compared to liquid nitrogen since these can only achieve temperatures of around −57°C compared with −196°C
• complications - pain, hypopigmentation or hyperpigmentation, and blistering. 
• combination therapy - cryotherapy and SA (1,3)

Other treatments used in secondary care include:

• immunomodulatory agents
• Imiquimod
• Diphencyprone 
• anti mitotic agents - Bleomycin
• curettage and cautery
• laser abalation
• photodynamic therapy (1,3)

The British Association of Dermatologists (BAD) guidelines do not recommend the following treatment methods due to insufficient evidence:

• citric acid
• formic acid
• H2 receptor antagonists
• herbal treatment
• hypnotherapy
• intralesional immunotherapy
• occlusotherapy (e.g. duct tape)
• retinoids, topical
• silver nitrate
• zinc oxide or Zinc sulphate (3)

Reference:

• (1) Lynch MD, Cliffe J, Morris-Jones R. Management of cutaneous viral warts. BMJ. 2014;348:g3339.
• (2) Primary Care Dermatology Society (PCDS). Clinical Guidance – Warts (November 2017)  
• (3) Sterling JC et al. British Association of Dermatologists' guidelines for the management of cutaneous warts 2014. Br J Dermatol. 2014;171(4):696-712.