(BQ) Part 2 book Evidence-Based dermatology presents the following contents: The evidence (infective skin diseases, exanthems and infestations; disorders of pigmentation; common ailments with significant cosmetic impact, other important skin disorders), the future of evidence-based dermatology.
S E C T I O N 3 Infective skin diseases, exanthems, and infestations Masutaka Furue and Yuping Ran, editors CHAPTER 38 Local treatments for cutaneous warts Juping Chen1 and Yan Wu2 Department of Dermatology, Second Clinical Medical College of Yangzhou University, Yangzhou, China Department of Dermatology, No.1 Hospital of China Medical University, Shenyang, China Background Definition Cutaneous warts are extremely common, benign, and usually selflimiting Infection of epidermal cells with the human papilloma virus (HPV) results in cell proliferation and a thickened, warty papule on the skin The most common sites involved are hands and feet, though any area of skin can also be infected Genital warts are also common and frequently sexually transmitted, but are not discussed in this chapter Prevalence There are few reliable, population-based data on the prevalence of cutaneous warts The prevalence rate varies according to different ages, populations, and periods of time, and it is the highest in children and young adults Two large population-based studies revealed prevalence rates of 0.84% and 12.9% [1,2] Studies in school populations showed rates of 12% in 4–6-year-olds and 24% in 16–18-yearolds [3,4] Etiology and risk factors Warts are caused by HPV, of which there are over 70 different types Lesions are most common at sites of trauma, and probably result from inoculation of virus into minimally damaged areas of epithelium Plantar warts are often acquired from common bare-foot areas; severe hand warts showed an occupational risk in butchers and meat handlers [5,6] Prognosis Non-genital warts in immunocompetent people are harmless and usually resolve spontaneously as a result of natural immunity within months or years The rate of resolution is highly variable and probably depends on a number of factors, including host immunity, age, HPV type, and site of infection One frequently cited study of an institutionalized population showed that two-thirds of warts resolved within a 2-year period [7] Evaluation of clearance rates in control groups in randomized controlled trials (RCTs) may also give some indication of natural clearance tendency, although a nonspecific benefit of vehicle bases may make interpretation difficult Twenty-three RCTs discussed in this chapter showed an average cure rate of 18% (range 0–73%) with placebo preparations after an average period of 10 weeks (range 4–24 weeks) Diagnostic tests Warts are frequently diagnosed clinically Microscopic examination obtained surgically can confirm the diagnosis if there is doubt HPV typing is used in research laboratories and occasionally in medicolegal cases to investigate child abuse Aims of treatment To clear warts completely and permanently Relevant outcomes • Cure rate (total clearance rate); • recurrence; • adverse reactions, such as pain and blistering Methods of search Data sources and search strategy All RCTs on the topical treatments for extragenital warts were identified, without limitation of language or publication status The Medline, Embase, Cochrane Library, the Meta Register of Controlled Trials, CBM, and CNKI were searched Reference lists of prior reviews, systematic reviews, and trials were also checked The most recent searches were completed in June 2012 Study selection and data extraction Two investigators independently screened studies for inclusion, retrieved potentially relevant studies, and determined eligible studies Disagreements were resolved by consensus Two investigators independently extracted data from the included studies using Evidence-based Dermatology, Third Edition Edited by Hywel C Williams, Michael Bigby, Andrew Herxheimer, Luigi Naldi, Berthold Rzany, Robert P Dellavalle, Yuping Ran, and Masutaka Furue © 2014 John Wiley & Sons, Ltd Published 2014 by John Wiley & Sons, Ltd Companion Website: www.evidencebasedseries.com/dermatology 320 Local treatments for cutaneous warts 321 custom-made standardized forms and a third investigator was assigned with the checking process active treatment group developed cellulitis Minor skin irritation was noted occasionally in some trials Quality assessment Comments The criteria recommended by the Cochrane Collaboration Handbook were used to assess the methodological quality of included trials It mainly focused on description of randomization (sequence generation progress), allocation concealment, blinding, addressing of incomplete outcome data, reporting of selective outcome, and other potential threats to validity [8] The judgment for each entry was based on the answer of a question, with “yes” indicating “low risk of bias,” “no” indicating “high risk of bias,” and “unclear” indicating “either lack of information or uncertainty over the potential for bias” [8] Disagreements were resolved by group consensus Outcomes measurement The primary outcome is the cure rate (total clearance rate) The secondary outcome is adverse reactions Statistical analysis All statistical analyses were performed using the duplicate data entry facility of Revman 5.0.25 (evidence-based medicine software) by two investigators [9] In addition to 95% confidence intervals (CIs), relative risks (RRs) and mean differences (MDs) were respectively used for dichotomous and continuous outcomes The χ2 (chisquare test) statistic was calculated to determine the proportion of between-study variation due to heterogeneity The value ranged from to 100%, and high values indicated strong heterogeneity If heterogeneity was low (P > 0.1, χ2