Warts (verrucae) are caused by the human papillomavirus and may regress spontaneously at any time within months or years of their first appearance. However, particularly in immunosuppressed patients, they may become widespread and difficult to cure.

Treatment

Many common, plane and plantar warts can be left untreated, but painful or unsightly lesions generally respond to application of paints or lotions containing salicylic acid. Where available, liquid nitrogen applied with a cotton-tipped swab or a spray is highly effective. However, caution is required, since freezing can cause temporary or permanent depigmentation of the skin.

Genital warts (condylomata acuminata), which are transmitted by sexual contact, should always be treated, even though they frequently recur, since they may increase the risk of cervical cancer. Podophyllum resin, 10-25% in compound tincture of benzoin, should be applied carefully and sparingly to external genital, perianal and vaginal warts at weekly intervals up to a maximum of four applications; normal tissue should be avoided. Resin applied to the vaginal mucosa should be allowed to dry before it comes into contact with normal epithelium. Where it is available, podophyllotoxin is a less toxic alternative that can be applied by the patient. Trichloroacetic acid may be applied directly to the wart, but it is less effective and the treated area should be powdered with talc or sodium bicarbonate to remove excess acid.

External applications of podophyllum resin and podophyllotoxin should be removed by washing after 1-4 hours. Podophyllum resin is readily absorbed, locally destructive and teratogenic. Neither podophyllum resin nor podophyllotoxin should be applied to large skin surfaces, nor should they be used during pregnancy.

Surgical removal, electrocautery, cryosurgery and laser treatment may be used for genital warts when topical applications have failed or are contraindicated. Topical application of fluorouracil, 5% ointment, and intralesional or systemic administration of an interferon are also reported to be of value in resistant cases, but these treatments are expensive.