It is the purified and standardized active ingredient of podophyllin (see below). Podofilox is safer and more effective than podophyllin. Skin erosion and pain are more commonly reported than with imiquimod and sinecatechins. Its use is cycled (2 times per day for 3 days then 4–7 days off); one review states that it should only be used for four cycles. Imiquimod is a topical immune response cream, applied to the affected area. It causes less local irritation than podofilox but may cause fungal infections (11% in package insert) and flu-like symptoms (less than 5% disclosed in package insert). Sinecatechins is an ointment of catechins (55% epigallocatechin gallate) extracted from green tea and other components. Mode of action is undetermined. It appears to have higher clearance rates than podophyllotoxin and imiquimod and causes less local irritation, but clearance takes longer than with imiquimod. Trichloroacetic acid (TCA) is less effective than cryosurgery, and is not recommended for use in the vagina, cervix, or urinary meatus. Interferon can be used; it is effective, but it is also expensive and its effect is inconsistent.DiscontinuedA 5% 5-fluorouracil (5-FU) cream was used, but it is no longer considered an acceptable treatment due to the side-effects.Podophyllin, podofilox and isotretinoin should not be used during pregnancy, as they could cause birth defects in the fetus. Epidemiology
Genital HPV infections have an estimated prevalence in the US of 10–20% and clinical manifestations in 1% of the sexually active adult population. US incidence of HPV infection has increased between 1975 and 2006.
Signs and symptoms
They may be found anywhere in the anal or genital area, and are frequently found on external surfaces of the body, including the penile shaft, scrotum, or labia majora of the vagina. They can also occur on internal surfaces like the opening to the urethra, inside the vagina, on the cervix, or in the anus.They can be as small as 1-5mm in diameter, but can also grow or spread into large masses in the genital or anal area. In some cases they look like small stalks. They may be hard ("keratinized") or soft. Their color can be variable, and sometimes they may bleed.In most cases, there are no symptoms of HPV infection other than the warts themselves. Sometimes warts may cause itching, redness, or discomfort, especially when they occur around the anus. Although they are usually without other physical symptoms, an outbreak of genital warts may cause psychological distress, such as anxiety, in some people. Causes
Transmission
HPV is most commonly transmitted through penetrative sex. While HPV can also be transmitted via non-penetrative sexual activity, it is less transmissible than via penetrative sex. There is conflicting evidence about the effect of condoms on transmission of low-risk HPV. Some studies have suggested that they are effective at reducing transmission. Other studies suggest that condoms are not effective at preventing transmission of the low-risk HPV variants that cause genital warts.