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MedicineToday 2014; 15(10): 34-43

PEER REVIEWED FEATURE 2 CPD POINTS

Treating cutaneous warts What are the options? Key points BRUCE TATE MB BS, PhD, FACD • Most people develop cutaneous warts at some First-line treatments for cutaneous warts include freezing and home time in their life; around 65% of warts regress spontan­ topical therapy with preparations combined with plus eously within two years. heating, paring and zinc oxide cream. If prolonged use of these • Prevalence of warts is treatments fails or they are unsuitable then a wide range of chemical, increased in patients with reduced cellular immunity immunological and physical treatment options are available. and genetic conditions such as epidermodysplasia arts are caused by with a infection and the commonly associated HPV verruciformis. human papillomavirus (HPV). Most genotypes are outlined in the Table.5 • First-line treatments for people develop cutaneous warts at cutaneous warts include some time in their life, with a point CLINICAL PRESENTATION freezing and home topical W prevalence of 20% among Australian school The clinical presentation of warts depends on therapy with a salicylic acid children, slowly declining with increasing the infecting HPV genotype and the site affected. preparation plus heating, age.1-3 Common warts (verruca vulgaris) occur on the paring and zinc oxide cream. Papillomaviruses are closely related to hands, fingers, elbows and knees. These warts • When prolonged use of ­nonenveloped DNA and are highly occur particularly on the fingers (including first-line treatments fails or is species-specific. HPVs show considerable diver- periungual or subungual sites) but also on the unsuitable, then treatment sity; the complete DNA sequence is known for dorsal area of the hands (Figure 1). options include: about 120 HPV genotypes, and partial DNA Palmar and plantar warts may be solitary – chemical therapies such as sequences for at least another 80 genotypes.4 or multiple. On the soles, mosaic warts are more caustic agents, DNA sequencing reveals a phylogenetic tree superficial plantar warts that have coalesced – immune system modifiers where the groupings match their biolog- into larger plaques, usually on weight-bearing such as diphencyp­rone, ical behaviours. The clinical subtypes of HPV sites (Box 1, Figures 2a to c). Myrmacia (Latin , cimetidine – physical therapies such as duct tape occlusion, Dr Tate is a Dermatologist in St Albans and Yarraville, and at Western Hospital and the Skin Foundation Copyright _Layout 1 17/01/12 1:43 PM Page 4 destructive treatments. Victoria, Melbourne, Vic. © SHUTTERSTOCK/XRENDER. HUMAN PAPILLOMAVIRUSES

34 MedicineToday x OCTOBER 2014, VOLUME 15, NUMBER 10 Downloaded for personal use only. No other uses permitted without permission. © MedicineToday 2014. for anthill) are thicker endophytic plaques of TABLE 1. CLINICAL SUBTYPES OF HPV INFECTION AND THE COMMONLY wart sloping to a central depression. Occasion- ASSOCIATED HPV GENOTYPES ally, large confluent plaques of plantar warts occur. Palmar and plantar warts are usually Infection type HPV genotypes* painless but can sometimes be surprisingly painful, particularly when on weight-bearing Skin sites. Common warts (hands, fingers, elbows, knees) 1, 2, 4, 27, 57 Plane (flat) warts are more subtle than Treating Palmar and plantar warts 1, 2, 27, 57 ­common warts, presenting usually with numerous, flesh-coloured to slightly red-brown Mosaic warts (soles) 2 or small plaques. They most often Myrmecial warts (soles) 1 occur on the dorsum of the hands or nearby cutaneous forearms and are also seen on the face and neck Plane (flat) warts 3, 10 (Figure 3). Epidermoid cysts of the sole (with inclusion bodies)† 4, 57, 60, 63, 65 Rarely seen are epidermoid cysts of weight-bearing areas of the sole. These contain Butcher’s warts (mainly seen in meat or fish workers) 7 (not animal sourced) mainly HPV type 60 – one of a number of HPV warts Digital squamous cell and Bowen’s disease 16 genotypes that cause warts with inclusion bodies What are the options? seen on . Epidermodysplasia verruciformis (EV)† 3, 5, 8 (and many others) † PATHOGENESIS EV 5, 8 Wart infection occurs: Mucosa • directly via skin-to-skin contact, either Anogenital warts (condylomata acuminata) 6, 11 from person to person or through auto­ inoculation to adjacent skin Higher-grade intraepithelial neoplasias (cervical warts, 16 • indirectly via contaminated surfaces and penile , erythroplasia of Queyrat) objects such as showers in the home, at Invasive (cervix, vulval, penile, oral) ‡ swimming pools or gymnasiums. 16, 18, 31, 45 Infection is promoted by minor abrasions Warty (condylomatous) squamous cell carcinoma 16 and maceration that allow HPV access to basal Oral warts 6, 11 keratinocytes. The circular DNA of HPV becomes a replicon in the nuclei of epithelial Heck’s disease (oral focal epithelial hyperplasia)† 13, 32 (only) basal cells, creating a long-term reservoir of Conjunctival 6, 11 viral DNA. The incubation period is up to 20 months for experimental HPV , Nasal inverting papillomas† 11, 57 but clinical experience suggests it may be con- siderably longer in some cases. Approximately Recurrent respiratory papillomatosis 6, 11

65% of warts regress spontaneously within ABBREVIATION: HPV = human papillomavirus. two years.6 * Many more HPV genotypes are less often linked to some of these clinical forms.5 Warts can be persistent and have high recur- † Occur rarely. ‡ These four genotypes account for around 80% of cervical cancers. rence rates. Furthermore, treatment may not prevent further HPV (although the risk is low if the warts are not clinically immune defences through mechanisms apparent). Possible reasons include: that include the absence of a viraemic • the persistence of HPV DNA in phase in HPV infection, which minimises ­normal-appearing skin surrounding the the systemic immune response; and warts, as shown by polymerase chain low-level expression of viral proteins in reaction (PCR) the lower ­layers of the where • the resistance of HPV to heat and antigen-­presenting cells are most prevalent. desiccation Copyright _Layout 1 17/01/12 1:43 Eventually,PM Page 4 protective type-specific • the ability of HPV to evade the host’s immunity does develop.

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mutations in the TMC6 or TMC8 genes, suppress known human tumour suppres- which encode transmembrane proteins sor proteins. This mechanism allows pro- involved in zinc transport). Onset is usu- liferation of the viral genome in tissues ally in childhood. Clinically, this condition that routinely ‘turn off’ cell proliferation is highly polymorphic with widespread as the epithelial cells differentiate. Non­ lesions usually resembling plane warts or oncogenic HPV genotypes lack these ­pityriasis versicolor. ­proteins. The incidence of HPV-related HPV infection is responsible for the vast malignancies is higher in people with a majority of cases of cervical carcinoma, deficiency in cell-mediated immunity or and HPV vaccination will likely signifi- epidermodysplasia verruciformis.5 Figure 1. Moderate-sized common cantly reduce the incidence of this carci- warts (verruca vulgaris) on the finger in the future.7,8 HPV infection is also DIFFERENTIAL DIAGNOSES and subungual area of the thumb. strongly linked to a­ nogenital squamous Corns or cell carcinoma (SCC) and some SCCs of Corns or calluses are the main differential the head and neck. Other HPV-a­ ssociated diagnosis but are uncommon in younger Some conditions associated with an conditions prone to transforming to inva- people. Repeated focal pressure or friction increased prevalence of warts are shown sive SCC are the higher-grade intraepithe- causes protective thickening of the skin, in Box 2. Warts are much more prevalent lial neoplasias of male or female genital making that area firmer and more prom- in people with reduced cellular immunity. sites (cervical warts, penile bowen­oid inent, leading to a vicious cycle. Corns and Epidermodysplasia verruciformis is a rare ­papulosis and erythroplasia of Queyrat) calluses on the hands are mainly seen in genetic disease that involves infections and inverted (mostly seen in the manual workers and on the feet from poor with HPV genotypes that do not produce nasal cavity). fitting footwear, abnormally shaped feet warts in normal individuals. The ­disease Only some HPV genotypes are onco- or bony prominences on weight-bearing is mostly autosomal recessive (caused by genic, as they encode proteins that sites.

1. CASE: A YOUNG MAN WITH MOSAIC PLANTAR WARTS

Presentation Treatment A 19-year-old man presented with mosaic warts on the left I explained to the patient that warts of this type are often slow sole and smaller warts elsewhere on his soles, fingers and the to respond to treatment and that he had not used the treatments dorsum of his hands (Figures 2a to c). He swam regularly and for long enough to give them a fair trial. We elected to pare played soccer. He had used a proprietary wart paint daily for a and solid freeze the warts, followed by combination home month with no benefit. His GP froze the warts on two occa- topical therapy. This comprised hot water soaks followed by sions two weeks apart. No developed; some of the application of 17% salicylic acid and 17% lactic acid in a warts on the dorsum of his hand cleared but most persisted. collodion base at night and zinc oxide cream during the day, The patient then used a wart home freezing device three times both under occlusion with a dressing tape. The patient did not over three weeks with no benefit. return for follow up.

Figures 2a to c. CopyrightMosaic warts _Layout on the1 17/01/12 left heel and1:43 smaller PM Page warts 4 elsewhere on the soles in a 19-year-old man.

36 MedicineToday x OCTOBER 2014, VOLUME 15, NUMBER 10 Downloaded for personal use only. No other uses permitted without permission. © MedicineToday 2014. and tinea 2. CONDITIONS ASSOCIATED Psoriasis purely of the palms and soles may WITH AN INCREASED be a distinct entity to psoriasis vulgaris, PREVALENCE OF WARTS5 but the latter may include palms and soles as well as other sites. The plaques are well • HIV infection demarcated, red and scaly and vary from • Organ transplantation involving small, localised areas to conflu- • Some haematological malignancies ent over most of the palms or soles. They (e.g. chronic lymphocytic leukaemia can be thick and fissured. Sterile pustules and Hodgkin’s disease) may be present. Tinea should also be considered. • Idiopathic CD4 lymphopenia Figure 3. Multiple plane warts on the • Some rare genetic immunodeficiency dorsum of the hand and fingers. Hypertrophic syndromes (e.g. common variable Hypertrophic lichen planus most often immunodeficiency, severe combined occurs on the legs and dorsal area of the immunodeficiencies, ataxia– Corns are more focal with a hard kerat- feet. The thickened scaly plaques have a telangiectasia, Fanconi’s anaemia, inous seed; calluses are broader. Except for livid hue and are usually itchy; the thick- Wiskott–Aldrich syndrome, DOCK-8 the central seed of a corn, paring with a ening results from repeated scratching. deficiency, WHIM syndrome, WILD surgical blade shows persistence of the syndrome) normal skin markings, which are absent Rare disorders • Epidermodysplasia verruciformis in the heart of a wart. Warts often also show Punctate palmoplantar black dots from thrombosed capillaries include a number of rare inherited disor- and bleeding from capillaries from more ders, punctate porokeratosis and arsenical The treatment recommendations superficially located dermal papillae. These keratoses. The dorsal surfaces are usually below are based on personal experience features may be clearer with dermos­copy. spared. and evidence from clinical trials. Using Macerated interdigital warts are difficult Tuberculosis verrucosa cutis is rare in the strict criteria of evidence-based med- to distinguish from (soft) interdigital corns. Australia but should be considered in icine, a recent Cochrane review concluded immigrants from endemic areas. It occurs that of the treatment options for warts, Neoplasms in individuals who have been previously only topical salicylic acid preparations are (epithelioma cunic- infected with Mycobacterium tuberculosis superior to placebo.9 Another similar ulatum type) is a rare low-grade, well-­ after exogenous inoculation with this review concluded that ‘significantly higher differentiated SCC on the soles of older bacterium at sites prone to trauma. The remission rates may be expected only with adults. The term ‘cuniculatum’ refers to a lesion begins as a small, subtly inflamed and salicylic acid used in rabbit burrow-like appearance with deep wart-like , which gradually enlarges combination’.10 These conclusions are dif- furrows. Verrucous can grad- to a firm red-brown verrucous plaque. ficult to assess as there are few properly ually penetrate, destroying the subcutis, controlled, adequately sized trials to com- fascia or bone, and often recur after TREATMENT OF WARTS pare the range of available treatments. attempted removal but rarely metastasise. There are few specific antiviral therapies Despite this, many less adequately con- In the past, they were thought to result to treat HPV infection. Most therapies aim: trolled trials report high response rates to from HPV infection but stricter histo- • to physically remove visible warts the investigated treatments. pathological criteria suggest this is an • to be cytotoxic to infected cells or uncommon factor.9 • to induce an immune response Treatment selection Rarely, in situ SCC (Bowen’s disease) against the wart. Therapies may be divided into home ther- occurs between multiple toes or as peri- As warts are benign and self-limiting, apies and those administered by a clini- ungual or subungual disease with warty patients – especially children – may not cian. Combinations of therapies are often change and/or granulating erosive change. require treatment, and therapy likely to used. Some treatments are more suitable HPV infection is probably a common aeti- induce permanent scarring should be for anogenital warts than for plantar warts ological factor.10,11 This clinical presenta- avoided. There is no evidence that aggres- and vice versa. This article concentrates tion can also signify subungual , sive removal of warts results in a better on therapies likely to be used by general which is often amelanotic.Copyright If _Layout there is 1 any 17/01/12 long-term 1:43 PM outcome Page 4 nor that temporary practitioners, podiatrists and dermatolo- doubt then biopsy is mandatory. interruption of therapy is a problem. gists for cutaneous warts. Treatment

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Advice to patients reduce viral load and to apply povidone 3. SOME TREATMENT OPTIONS FOR CUTANEOUS WARTS It is important to explain to patients that iodine ointment daily to the healing skin. all available wart treatments are slow to Healing usually takes a week or two so the First-line treatments work and unreliable (prone to failure) and treatment is less suitable for physically active • Cryotherapy (e.g. liquid nitrogen) that warts are prone to recur after appar- people. ently successful treatment. No single treat- If the warts do not clear or recur after a • Home topical therapy ment is much more effective than others. single freeze then the next main options – heat (microwavable seed bags or A rule of thumb is that the success rate for are repeated cryotherapy or home topical hot water) any individual treatment modality is therapy. Cryotherapy is usually repeated – salicylic acid preparations approximately 70% after three months or every two to three weeks until the warts – zinc oxide cream longer of treatment. If a treatment appears clear, which may require many treatments. Other treatments* to have had a partial effect by three months It is common for children not to be pre- • Chemical therapies: cantharidin, and is tolerated then I encourage patients pared to return for multiple treatments – a caustic agents, formic acid, to continue with that treatment for a few point that I emphasise to parents insisting , 5-, oral more months before abandoning it. on aggressive treatment. Studies have inves- retinoids, , Preventive measures, such as wearing tigated more frequent freezing, with thongs when showering and not picking ­marginally improved results. • Immune system modifiers: sensitising at warts, are also important (the latter may Clinicians should be aware that melano- agents (e.g. diphencyprone), spread the HPV infection or allow peri- cytes are more sensitive to cryotherapy, so imiquimod, cimetidine, therapeutic ungual warts to develop). hypopigmentation (temporary or long-term) vaccination, intralesional or is a risk in darker skinned people. This is antigens AN APPROACH TO TREATMENT less of an issue on the feet than on the hands. • Physical therapies: home freezing After discussion of the treatment options Freezing is prone to lead to a ‘donut’ of with dimethyl ether plus propane, with the patient, a useful approach is as ­recurrent warts around the freeze site. duct tape occlusion, destructive follows. The use of this approach in a A home freezing device that uses treatments such as , patient with mosaic warts is outlined in dimethyl ether and propane is claimed electrosurgery, Box 1.11-13 to be effective for treating warts. In my • Others: photodynamic therapy, folk experience, this treatment often fails. A remedies Freezing study found the achieved minimum

* Options when warts do not respond to prolonged use Solid freezing should be offered because a temperature of 0°C at 40 seconds (com- of first-line treatments or when first-line treatments single freeze occasionally clears warts. Thick pared with -20°C at 20 seconds for liquid are unsuitable. warts may be pared with a blade. With liquid nitrogen) was probably insufficient for nitrogen (boiling point -196°C), the freeze therapeutic effect.14 In addition, patients options for cutaneous warts are summa- time needs to be long enough to induce blis- probably often do not adequately follow rised in Box 3. ters but not cause deep . Application the instructions because of pain. Important factors in deciding which is equally effective with cryo­sprays or thick modalities to use for a specific patient are: cotton tip applicators but the latter often Home topical therapy • likely effectiveness requires longer application times to achieve Home topical therapy is a good alternative • cost of the product or of repeated the same level of freezing. or adjuvant to freezing. It is cheap, conven- ­visits to the practitioner Freezing is painful and most young ient and minimally painful. I recommend • which treatments have been tried children will not tolerate it. Topical local that patients combine daily application of previously and their adequacy (e.g. anaesthetics are not effective enough for a compounded or proprietary salicylic acid appropriateness for site, compliance, the freeze times required. Various methods preparation with physical treatments such number of attempts and duration of of distraction may allow braver children to as heating and paring of the wart and appli- treatment) tolerate it. I explain that freezing does not cation of zinc oxide cream. Details of this • likely compliance and issues that kill HPV but rather destroys the skin har- strategy are shown in Box 4. affect this (e.g. pain, particularly for bouring it, so hopefully exposes the virus Products often claim to remove warts children or people who are constantly to allow immune recognition. However, rapidly. I explain to patients that many on their feet, practicality and time warts often re-appear in the healing skin. months of treatment are required before constraints) Copyright _Layout 1 17/01/12 I1:43 also PM instruct Page patients 4 or their carers to the ­treatment should be abandoned as • side effects. snip off the roof of the resulting to ineffective.

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do not associate any later pain with the 4. A HOME THERAPY STRATEGY FOR CUTANEOUS WARTS treatment and so are usually prepared to return for repeat therapy. 1. Heat the warts for 15 to 30 minutes every evening Preparations include 0.7% cantharidin This is reported to be an effective stand alone modality. Heating can be achieved in a film-forming base and 1% cantharidin with m­ icrowavable flax-seed hot bags or by soaking the feet or hands in a baking plus 20% salicylic acid and 2% podophyl- dish or bowl of water at a temperature that is almost uncomfortable. lum in a collodion base. They are not avail- 2. Dry the feet or hands and apply a wart paint under dressing tape overnight able from most . Cantharidin I recommend 40% salicylic acid compounded in white soft paraffin as a cheap is only for office use: a thin smear is applied wart paint (made up by the pharmacist on prescription). Over-the-counter ­proprietary to each wart and allowed to dry. Occlusion ­alternatives are available with a similar formulation (17% s­ alicylic acid and 17% lactic acid in is not required but if used increases the a collodion base; including Dermatech, Duofilm Liquid and Wart Clear Solution). Collodion intensity of the blister. Some recommend dries to form a rubbery film. Collodion also contains colophony, a common cause of a­ llergic washing cantharidin off a few hours after contact (as seen with some brands of fabric adhesive tape). Another proprietary application but removal is difficult and is option (Wart-Off Paint) contains 20% salicylic acid, 12% ­lactic acid and 10% podophyllum not needed. Cantharidin is applied every resin in an ether– base. one to two weeks until new warts stop Any of these paints should be applied moderately generously each night to each wart, appearing; usually many applications are and then occluded overnight with dressing tape (e.g. Micropore), which is removed the needed. Zinc oxide cream can be applied next morning. on the days cantharidin is not applied. Bleomycin. This agent is 3. Remove the soft surface of the warts each morning with a pumice stone or file and apply 36% zinc oxide cream generously, also under dressing tape injected into each wart. It binds DNA caus- If daytime topical treatment is undesirable, such as for cosmetic or time reasons, ing single-strand breaks. It is used only for then oral zinc sulphate is an alternative (10 mg/kg to a ­maximum dose of 600 mg recalcitrant warts and is made up in syringes daily for two months). There are trials ­suggesting that either form of zinc has efficacy. by hospital pharmacies so is available only If the warts become too sore then the night-time treatment is temporarily stopped through outpatient clinics. and re-started once the discomfort settles, initially applied every second day and Protocols vary, but typically bleomycin then daily if tolerated. The morning t­reatment is bland so is continued. sulphate 0.25 to 1 mg/mL is injected up to If the warts appear to clear then the treatment is stopped but if the warts recur it is three times to a maximum total dose of 4 recommenced. If time is limited then the heating step can be omitted. mg. The injections are very painful so prior local anaesthetic is used. The area may remain painful for a week or so after treat- OTHER TREATMENT OPTIONS . Glutaraldehyde is a bac- ment. The warts develop haemorrhagic If the warts fail to respond to prolonged teriocidal and virucidal antiseptic. A 10% necrosis by two to three weeks, which can use of the above treatments or there are glutaraldehyde solution in a water-ethanol be removed by paring. Reported cure rates issues with the treatments then a range of base is available as a wart treatment vary from 14 to 99%. Systemic toxicity does options exist. (Diswart). It is prone to causing allergic not occur with this method but it is not so I do not recommend suitable in pregnant women. Local compli- Chemical therapies its use for warts. Treated skin hardens and cations include nail loss or dystrophy for Caustic agents. Repeat applications of turns a brown colour. periungual injections, Raynaud’s phenom- caustic agents are reported to be effective. Cantharidin. Cantharidin is available from enon in treated digits and local urticaria. These include monochloroacetic acid or some dermatologists and some hospital trichloroacetic acid, 35 to 80% in water or dermatology outpatient clinics. It is a Methods harnessing the immune 80% phenol, each applied weekly with a ­vesicle-forming terpenoid found in ‘blister system salicylic acid preparation on the other days. beetles’. It activates serine proteases that Diphencyprone (DCP). Also known as The acids cause immediate quite painful destroy epidermal desmosomal proteins, diphencyclopropenone, DCP is used for stinging that lasts for a prolonged time so so the healing blisters do not . more treatment-resistant multiple warts are less suitable for children. They also The application of cantharidin is not and can be very effective. It is available from cause temporary frosting of the skin, which painful. Blisters develop after hours to compounding pharmacies. Most patients is prone to later pigment change. Another two days, usually with no or manageable develop a delayed hypersensitivity reaction option is 10% silver nitrateCopyright in water, _Layout applied 1 17/01/12 pain, 1:43 and PM heal Page within 4 a week. Cantharidin (allergic contact dermatitis) to DCP and every second day for months. is particularly useful in children who often this immune attack is probably responsible

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for clearing warts. Squaric acid dibutyl ester required reaction. It can also be used as a ­Penetration may be enhanced by repeated is an alternative sensitising agent. Because liquid, usually in acetone at a lower concen- paring of the warts, cryotherapy, occlusion these chemicals are used only for wart ther- tration (0.01 to 0.05%) and can be applied and/or concurrent use of salicylic acid. An apy, the allergy is of limited consequence. from daily to weekly to maintain the required ideal treatment regimen has not been The clinician applies 2% DCP to a small moderate level of dermatitis. Some patients developed. area of normal skin to induce sensitisation become exquisitely allergic to DCP and Oral cimetidine. Oral cimetidine (30 to (dermatitis at the site) within 10 days. The develop more severe local reactions or wide- 40 mg/kg daily in two divided doses to a patient then applies 0.1% DCP and 15% spread urticarial or eczematous reactions. A maximum of 2400 mg daily for three to salicylic acid in white soft paraffin to the marked reduction in DCP concentration four months) stimulates production of some warts, initially a small amount every third will sometimes allow continued treatment cytokines. Initial uncontrolled studies day. The treated area must be carefully in these situations. I also prescribe a potent ­suggested efficacy, but two double-blind, taped to ensure the DCP does not contam- topical corticosteroid so it is available to treat ­placebo-controlled studies failed to confirm inate other sites as it will cause contact a too strong local reaction. DCP usually takes efficacy for recalcitrant common warts.15,16 dermatitis wherever it touches the skin. If months (sometimes six to 12) to clear warts. Therapeutic vaccination. The commonly no reaction occurs by a week after DCP Imiquimod. Imiquimod activates the innate used HPV is effective against and application then the frequency of applica- immune system via toll-like receptor 7, specific to HPV types 6, 11, 16 and 18 and tion is slowly increased to each night, and ­causing mild to substantial inflammation. is effective in preventing most anogenital then the amount applied is gradually Available as sachets of 5% imiquimod cream, warts. The therapeutic use of HPV vaccines increased, aiming to achieve a low to mod- it is expensive, not covered by the PBS for for already present anogenital and mucosal erately active persistent local dermatitis. this indication and is mainly used to treat warts has not been reported as yet. Similarly, Some patients need to apply DCP only genital warts, basal cell carcinomas and solar there are no trials on the therapeutic use of every few days to maintain the dermatitis. keratoses. It has poor penetration through these vaccines for cutaneous warts, but one Occasionally the concentration of the DCP keratin so is unlikely to work on areas with group has reported clearance of recalcitrant must be increased to 0.2% to achieve the thick skin such as the palms and soles. cutaneous warts in six patients.17,18 Despite

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Downloaded for personal use only. No other uses permitted without permission. © MedicineToday 2014. the vaccine being active against HPV geno­ of 5-fluorouracil used either alone with CONCLUSION types not usually found in cutaneous warts, tape occlusion or mixed with 10% salicylic Warts are an unpleasant and embarrassing it may have an effect in some patients via acid cream.21,22 viral infection experienced by most people. epitopes shared by cutaneous and anogen- Oral retinoids (acitretin or isotretinoin). On the more serious side, some genotypes ital HPV genotypes. The ability of HPV These can help debulk warts by reducing have oncogenic potential, and a small vaccines to prevent the development of epidermal proliferation. The infection ­number of patients with deficiencies in common cutaneous warts has not been usually persists, so relapse is likely on cell-mediated immunity can suffer over- investigated. Vaccine development is ongo- ­stopping treatment. Oral retinoids can be whelming numbers or very large warts. ing, raising the prospect of therapeutic helpful in patients with extensive hyper- Warts can be frustrating to treat and our vaccines against cutaneous warts. keratotic warts and immunosuppressed enthusiasm to treat can be tempered by the patients and to enhance the effectiveness fact that the majority resolve spontaneously Physical therapies of other treatments.23,24 in a few years. The many available treatments Duct tape. This occlusive plastic industrial Cidofovir. The antiviral agent cidofovir is make treatment choice ­confusing, and their adhesive tape is applied over the warts and a purine nucleotide analogue that can be unreliability and potential side effects frus- left on for four to six days. The wart is then extremely effective for plantar, anogenital, trating. There is a lack of large well-controlled debrided with a blade or pumice stone and oral and laryngeal warts, even in patients trials to best guide treatment. The develop- the duct tape reapplied in the same way. with immunodeficiency.25-27 It can be ment of HPV vaccines against anogenital Early studies of its use for two months administered by systemic infusion (5 mg/kg warts is e­xciting but these vaccines are showed complete clearance rates in 60 to once weekly), intralesional injection ­considered to have a very limited role in 85% of patients treated. However, later (2.5 mg/mL) or as a 1% gel or cream (avail- ­controlling cutaneous warts. MT ­placebo-controlled studies found poor able through compounding pharmacies). response rates.19,20 Side effects of systemic cidofovir include REFERENCES Destructive treatments. Destructive treat- nephrotoxicity and bone marrow suppres- A list of references is included in the website version ments such as excisional surgery, electro- sion, but topical treatment of skin lesions (www.medicinetoday.com.au) and the iPad app surgery and carbon dioxide laser treatment is usually well tolerated. Cidofovir is version of this article. are likely to cause scarring and should not expensive and so is infrequently used. be used for plantar warts on pressure-­ Adapalene. Adapalene 0.1% gel is a vitamin COMPETING INTERESTS: None. bearing sites as the firm become a A analogue used mainly as therapy. nidus for equally troublesome and difficult 85% formic acid solution. This is punc- to treat calluses or corns. These treatments tured into warts every second day up to Online CPD Journal Program can be used for recalcitrant warts on non- 12 times. weight-bearing sites. However, permanent Folk remedies. On the basis of scanty scarring is still an issue and warts not published literature and anecdotal reports, uncommonly recur, presumably as there repeated direct applications of banana may be wart virus in surrounding clinically peel, milk weed thistle latex and fig tree normal skin. Excisional surgery is not prac- latex have been recommended for the tical for large or numerous warts. Carbon treatment of warts.28,29 dioxide laser treatment is expensive. The Photodynamic therapy. This therapy smoke plume from electrosurgery and involves a topical photosensitiser and a carbon dioxide laser treatment may carry light source or pulsed-dye laser and is infective virus so has a small risk of causing mainly used to treat vascular lesions.30-32 The clinical presentation of warts airway warts in the people in the room. These techniques have cleared a significant depends partly on the infecting number of warts in small series. They are genotype of human papillomavirus. Less common treatments available from some dermatologists in True or false? Other treatments have been reported as private practice. successful in small series. They are used Intralesional injection. Injection of Review your knowledge of this topic infrequently. ­various vaccines or antigens into the larg- and earn CPD points by taking part in MedicineToday’s Online CPD Journal Program. 5 -fluorouracil cream (5%). This is a est wart can be successful. Antigens used chemotherapy agent used mainly to treat include Candida albicans, Trichophyton spp., Log in to solar . SignificantCopyright wart _Layout clearance 1 17/01/12 Propionibacterium 1:43 PM Page 4 acnes and , www.medicinetoday.com.au/cpd rates have been shown in a number of trials and vaccine or antiserum.

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BRUCE TATE MB BS, PhD, FACD REFERENCES

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