THERAPEUTIC APPROACHES FOR GENITAL WARTS

Treatment goals

External genital warts should be treated because of the rare but real risk of progression to cancer as well as to reduce the possibility of HPV transmission and relieve patients of the psychosexual burden they may experience. The ideal outcome of treatment for genital warts would be complete viral eradication. However, this ideal is not attainable, so elimination of the visible wart is the current treatment goal. Visible wart tissue is thought to harbour high numbers of virions. Therefore, removing visible warts should reduce the viral load, thereby reducing viral transmission. Other therapeutic goals include prolonging disease-free periods and minimising the risk of malignant transformation.

Current therapeutic approaches: an overview

Current therapies for condylomata are limited to destruction of visible warts. Treatments may be categorised as topical, ablative, surgical or intralesional. Laser therapy and systemic or intralesional interferon injections are used less frequently than other treatments. Unfortunately, existing therapies do not yield a 100% response rate; in addition, recurrence rates are high and no current therapies eliminate the causative agent (Table 2). Many therapies require multiple and often painful treatments, and all have disadvantages.

The number of treatment modalities and their limitations complicates therapy, which must be individualised according to severity, anatomical location and clinical course. Additionally, probable side effects, patient tolerance, compliance, effectiveness, cost and the cost-benefit ratio of treatment must be considered. Furthermore, because HPV can often be found in adjacent normal skin and HPV DNA may remain in the basal layer as a reservoir of infection, warts often recur after treatment. Recurrence rates have ranged widely in clinical studies but recurrence appears to be common with current therapies. Recurrence may result from subclinical or latent infection in the patient or from reinfection by an infected partner. Indeed, new warts may begin to appear before the previous treatment site has healed.

Genital warts

Table 1. Current treatments for genital warts

Topical
Podophyllin resin
Podophyllotoxin
Trichloroacetic acid
5-FU cream

Ablative
Cryotherapy
Electrosurgery
C02 laser

Surgical
Excision

Intralesional
Interferon-a
Interferon-ß
AccuSite( Injectable Gel

Table 2. Analysis of current treatments for genital warts