April 25, 2001 -- They are far from life threatening. They aren't even a danger to your health. But the common skin warts that affect some one million Americans each year routinely cause significant pain and embarrassment.
Until now the best wart removal treatments have involved freezing them off, called cryotherapy; burning them off; or zapping them with lasers one by one. But a new study in Archives of Dermatology suggests a single injection developed to target the virus that causes warts represents a far more effective approach.
"We have treated more than 300 patients with this therapy now and have seen about an 80% success rate," study author Sandra Marchese Johnson, MD, tells WebMD. "We believe this treatment is at least as effective as cryotherapy, but in most patients we only had to treat one wart and all of them went away." Johnson is an assistant professor and director of clinical trials at the University of Arkansas for Medical Sciences in Little Rock.
Warts are noncancerous skin growths caused by infection with the human papillomavirus, or HPV. Skin warts, caused by one type of HPV, are most often found on the hands and feet, but they also can occur on the arms, leg, and face. They are commonly seen in children and teenagers. Genital warts, caused by another HPV type, are spread through sexual contact with an infected partner.
In this study, Johnson and colleagues injected single warts in 115 patients with two antigens commonly used to evaluate immune status. The researchers hoped the injections would help the patients develop an immunity to HPV that was strong enough to clear the treated wart and any others.
The researchers reported that 74% of warts treated with antigen injections disappeared, compared with 55% of those treated with cryotherapy. In fact, all warts disappeared in 78% of patients with multiple warts who were treated with the single injections.
Johnson says, "This therapy was able to trigger HPV-directed immunity, and we not only saw the resolution of treated warts but untreated warts as well."
Because many of the patients included in the trial had failed other treatments, Johnson and colleagues suggest the effectiveness of this immunotherapy may be even greater in the general population of wart sufferers. The approach, they add, may also prove useful in the treatment of cervical cancer, which can be caused by HPV infection.