Published on 18/03/2015 by admin
Filed under Dermatology
Last modified 18/03/2015
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Hilmi F. Recica and Imtiaz Ahmed
Evidence Levels: A Double-blind study B Clinical trial ≥ 20 subjects C Clinical trial < 20 subjects D Series ≥ 5 subjects E Anecdotal case reports
Warts are a common disease caused by infection with various strains of the human papilloma virus (HPV). They appear on different sites of the body and in various forms including common, flat, filiform, periungual, plantar, mosaic, and genital warts. Children most commonly present with common or periungual warts on hands and feet, whereas adults often present with common warts on the back of hands or filiform warts on the face and neck. Genital warts are discussed in another chapter.
Most warts resolve spontaneously with time. However, patients and children’s parents often ask for treatment because of pain, social stigma or concern over infectivity. In some cases warts cause ridicule, distorted self-image, impaired dexterity, worry over loss of employment, or a health and safety issue. Immunosuppressed patients may have extensive and resistant warts.
Most patients will treat themselves with over the counter preparations containing keratolytics before presenting to the dermatologist. Salicylic acid has the best evidence base and is the most commonly used therapy. It can be applied in various concentrations with or without occlusion. However, it requires frequent application and it may cause irritation of the surrounding skin. Cryotherapy with dimethyl ether and propane applicator, silver nitrate pencils and occlusive ‘duct tape’ are also available over the counter.
When a dermatologist sees patients with warts, the diagnosis and the possibility of spontaneous resolution and watchful waiting should be explained. The patient should be educated on how to apply topical preparations accurately. Keeping the warts well pared down with the use of a file or pumice stone after soaking is especially important for plantar warts. Young and healthy individuals with short duration of infection have the highest clearance rate. Cryotherapy with liquid nitrogen is one of the commonest treatments used by the dermatologist. Liquid nitrogen is applied with a cryo spray or a cotton bud. The wart should be frozen outwards from the centre to include a 2 mm rim of normal skin, and the freeze maintained for 5 seconds. Cryotherapy is best repeated at 2- to 3-week intervals. Hyperkeratotic warts should be pared before cryotherapy and plantar warts treated by two freeze–thaw cycles. This treatment is painful and not always well tolerated by young children. The treated warts are sore and may blister. In pigmented skin, post-treatment hypopigmentation and hyperpigmentation can be a problem. Cryotherapy with liquid nitrogen can be combined with other topical preparations. Cryotherapy with carbon dioxide snow or dimethyl ether applicators does not produce temperatures as low as liquid nitrogen and is less effective.
If cryotherapy is not successful then various other options are available including immunotherapy with diphencyprone (DCP), squaric acid, and intralesional mumps or Candida antigen. Intralesional bleomycin may be injected into the wart or the solution applied to the wart and then repeatedly pricked through with a lancet. Laser ablation, hyperthermia, curettage and cautery or even surgical excision of troublesome and resistant warts can be attempted but the risk of scarring and recurrence of the warts in the scar can be a problem. The pulsed dye laser (PDL), thought to target the rich capillary network in warts, can be effective. Photodynamic therapy (PDT) is another option; however, pain during and after ALA (aminolevulinic acid)-PDT is well recognized. Other treatments used occasionally include 5-fluorouracil, zinc, levamisole, cimetidine, topical and oral retinoids, and imiquimod.
Bunney MH, Nolan MW, Williams DA. Br J Dermatol 1976; 94: 667–79.
This paper looked into 11 trials with over 1800 patients. In a randomized blind trial involving 389 patients, salicylic acid with lactic acid paint was as effective as cryotherapy with liquid nitrogen. The salicylic acid with lactic acid paint comprised 17% salicylic acid, 17% lactic acid, and 66% flexible collodion. In another study of 382 warts, 84% of patients were cured after 12 weeks of salicylic acid with lactic acid paint application. A separate study showed a 44% clearance with salicylic acid and lactic acid paint versus 47% of patients applying 10% glutaraldehyde.
Cockayne S, Hewitt C, Hicks K, Jayakody S, Kang’ombe AR, Stamuli E, et al. BMJ 2011; 342: d3271.
A study on 240 patients treated by healthcare professionals with liquid nitrogen, for up to four treatments, 2 to 3 weeks apart, were compared with patient self-treatment with 50% salicylic acid daily, for up to 8 weeks. Overall, 14% had complete clearance at 12 weeks, with no significant difference between the two groups. Cryotherapy cost £100.00 more than salicylic acid.
Gibbs S, Harvey I, Sterling JC, Stark R. Cochrane Database Syst Rev 2003; CD001781.
According to 52 trials, meeting the criteria for inclusion in this review, the best evidenced therapy for cutaneous warts is for salicylic acid. Data pooled from six placebo-controlled trials, showed a cure rate of 75% in the salicylic acid group versus 48% in the placebo group.
Yazar S, Basaran EJ. J Dermatol 1994; 21: 329–33.
A randomized, placebo-controlled study with 35 patients in each group showed that, 1 month after treatment, 15 patients were cleared by three applications of a silver nitrate pencil, at 3-day intervals. Only four of the placebo group responded.
Ebrahimi S, Dabiri N, Jamshidnejad E, Sarkari B. Int J Dermatol 2007; 46: 215–17.
A topical solution of 10% silver nitrate, applied on to the warts on alternate days for 3 weeks, in 30 patients resulted in complete clearance in 63% of patients after 6 weeks in the treatment group versus no healing in the placebo group.
Nguyen NV, Burkhart CG. J Drugs Dermatol 2011; 10: 1174–6.
Other coolants are probably less effective than liquid nitrogen.
Youn SH, Kwon IH, Park EJ, Kim KH, Kim KJ. Ann Dermatol 2011; 23: 53–60.
In a retrospective study with 560 patients, a 2-week interval was compared with a 3-week interval between cryotherapy with liquid nitrogen. For the 2- and 3-week groups, cure rates were, 77% and 75%, respectively. Recurrence rates were 13% and 25%.
Two-week cryotherapy is optimal not only because of the rapid cure but also because of the lower recurrence rate.
Ahmed I, Agarwal S, Ilchyshyn A, Charles-Holmes S, Berth-Jones J. Br J Dermatol 2001; 144: 1006–9.
This prospective study of 363 patients compared application of liquid nitrogen with cotton wool bud versus cryo spray. After 3 months of treatment, liquid nitrogen cured 47% of patients with a cotton wool bud versus 44% with a cryo spray (p=0.8).
Bourke JF, Berth-Jones J, Hutchinson PE. Br J Dermatol 1995; 132: 433–6.
This study carried out on 225 patients showed a 45% cure rate for warts treated with liquid nitrogen. The mean times to clearance of warts in each group were 5.5, 9.5, and 15 weeks in the weekly, 2- and 3-weekly groups, respectively. The mean numbers of treatments needed to achieve clearance were similar in each group (5.5, 4.75, and 5 treatments). The study showed that clearance of the warts was related to the number of treatments received and it was independent of the interval between treatments.
Berth-Jones J, Bourke J, Eglitis H, Harper C, Kirk P, Pavord S, et al. Br J Dermatol 1994; 131: 883–6.
In a randomised trial 300 patients received cryotherapy with either one or two freeze–thaw cycles, at a 3-week interval. In addition, all subjects used keratolytic wart paints and plantar warts were pared prior to freezing. At 3 months, the cure rate was 57% from the single freeze technique versus 62% from the double freeze technique. In plantar warts, the cure rate was 41% from single freezing and 65% for double freezing whereas in the hand warts there was no additional benefit from the second freeze.
Treatment of Skin Disease Comprehensive Therapeutic Strategies 4e
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