By Lori Rodriques, M.D., Clinical Fellow, UCSF Dept. of Dermatology
| Tx/How Supplied | Wart | Dose | Comments |
| Podophyllin: 25% crude extract in a tincture of benzoin, applied by physician | Warts on moist surfaces | Every week, paint on lesion, wash off after 4-8 hours. Duration of 6 weeks |
Local irritation, ulceration, scarring.
Phimoses and balanitis can occur if podophyllin is used on the foreskin or glans penis.
Systemic side effects may include fever, nausea, vomiting, confusion, coma, ileus, renal failure, paresthesias, polyneuritis and leukopenia. Podophyllin is considered a teratogen and should not be used during pregnancy.
Complete response observed in 40% of patients after six consecutively weekly treatments.
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| Podophyllotoxin (Condylox): 0.5% gel or solution applied by patient | Warts on moist surfaces | BID for 3 consecutive days each week for 4-6 week treatment cycles | Success rates approach 60% and side effects are less than with the physician applied podophyllin preparations. |
| Cryotherapy with liquid nitrogen | All conditions | One to two freeze-thaw cycles are applied to each wart every 1 to 3 weeks | Freezing can be painful and may result in blister or ulcer formation. 80% of patients are free of warts during treatment and 55% are clinically negative 3 months after treatment is stopped. |
| Alternative: Trichloroacetic acid (TCA): 35%-85% solution | Genital warts | Weekly or biweekly | TCA has the same or lower efficacy compared to cryotherapy and results in more pain, ulceration, and is not readily available. |
| Imiquimod (Aldera) | Genital warts | Applied QD by patient on alternate days 3 days a week | A topical immunomodulator, has an efficacy similar to cryotherapy and yields a low recurrence rate. It is more effective than podophyllin in treating women with external genital warts, (72% response rate) and equal or less effective in men, especially lesions on the penile shaft (33% response rate). The response rate is slow, requiring at least 10 weeks of therapy before a response is observed. Local skin irritation occurs. |
| Electrosurgery | Condyloma | | Wart clearance occurs in 95% of patients with at least 70% of patients free of warts at 3 months. These methods are recommended for lesions that are small in size and number and can be done under local anesthesia. Scarring may result. |
| CO2 laser treatment | External genital warts | | 60-90% response rate with recurrence rates between 5% and 10%. The advantages are reduced bleeding and post-operative pain. Disadvantages include the high cost of laser surgery, increased healing time. This method should be reserved for patients with more extensive lesions. |
The continuum of HPV infection ranges from clinical, to subclinical, to latent disease. One percent of sexually active adults have clinically active disease. Five percent have subclinical lesions detected only by enhancing techniques such as acetowhitening. Twenty-five percent of sexually active adults have HPV DNA detected in areas without clinical lesions or in areas that are acetowhite negative -- this is latent disease. While the risk of transmission among persons with clinical active disease is not known, the majority of couples with visible genital warts have partners that are concordantly infected. The risk of transmitting the infection from persons with subclinical or latent infection is also unknown. Latent disease may be responsible for the persistence of infection despite therapy.
Etiology
Numerous HPV types can cause genital warts. In general, HPV types 6 and 11 are low-risk types and produce benign lesions. High-risk HPV types or those associated with anogenital cancer, most commonly in the transition zone of the cervix and anus, are usually caused by HPV types 16 and 18. In a small group, HPV infection persists and may progress to cancer. The exact mechanism for this is unknown.
Clinically, condyloma appear as soft sessile masses, that average 2 to 5 mm in size but may reach several centimeters in diameter and height. Lesions are frequently multifocal and in general, their color is gray, pale yellow or pink. In women, lesions appear on the vulva, cervix, and perineum or about the anus. In men, they can occur on the penis or perianal area, and less frequently on the scrotum. Patients are usually asymptomatic. However, trauma to lesions can cause bleeding, itching, or irritation. In addition, women may experience vaginal discharge.
Treatment of Genital Warts
Treatment is not shown to reduce the transmission to sexual partners nor to prevent the progression to dysplasia or cancer. Because genital warts are sexually transmitted, investigation for other sexually transmitted diseases is warranted. Women with genital warts or those whose partners have genital warts should have a routine cervical cytological screening (Papanicolaou smear) to detect cervical dysplasia. See table above for specific information on treatment.
References
- Baker G.E., Tyring S. Therapeutic approaches to papillomavirus infections. Inf Dis Dermatol. 1997, 15: 331-340.
- Odom R.B., James W.D., Berger T.G. Andrew's Disease of the Skin. 9th edition. Philadelphia, (PA); W.B. Saunders Co; 2000. pp 514-51.
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