Human papilloma virus are a group of DNA-based virus infecting skin and mucous membranes with more than 100 strains of which over 30 strains being sexually transmitted and infecting the genital area (genital HPV). HPV strains commonly cause warts and people may get infected by walking bare foot or wearing other’s shoes. The figure below depicts notable Human Papilloma Virus with associated diseases. HPV induced diseases include the following: 1. Skin warts 2. Genital warts 3. Cancer and 4. Respiratory papillomatosis. 1.
Skin warts: These include (i) Common warts (ii) Plantar warts (iii) Subungual or Periungual warts (iv) Flat warts. (i) Common warts: HPV types such as HPV – 1 and HPV – 2 cause common skin warts often occurring on hands and feet and also occurring on other areas such as knees or elbows with a characteristic cauliflower shape. These warts do not cause genital warts and are not associated with cancer. (ii) Plantar warts: They resemble common warts and are found on the soles of the feet. (iii) Subungual or Periungual warts: They form under the fingernail, around the fingernail or on the cuticle and are difficult to treat.
(iv) Flat warts: Generally found on face, forehead or arms occurring frequently in children and teenaged individuals. Flat warts are not associated with development of cancer in people with normal immune function. 2. Genital warts: A wide variety of HPV cause genital warts, but types 6 and 11 account for approximately 90% of all cases. People may pass on the infection to others not displaying the symptoms of infection. An important point to be noted is that HPV types that tend to cause genital warts do not cause cervical cancer. 3.
Cancer: About 12 HPV types including the types 16, 18, 31 and 45 can cause various types of cancers such as cervical cancer, anal cancer, vulvar cancer, penile cancer head and neck cancer and are called “high-risk” types. “HPV-induced cancers often have viral sequences integrated into the cellular DNA. Some of the HPV ‘early’ genes, such as E6 and E7 are known to act as oncogenes promoting tumor growth and malignant transformation. ” The graphical depiction in the next page clearly shows that HPV induced cancer of cervix are maximum as compared to any other types.
4. Respiratory papillomatosis: A rare condition known as recurrent respiratory papillomatosis may be cause by HPV types 6 and 11 with warts forming on the larynx and or other areas of respiratory tract. These may occur frequently requiring repetitive surgery due to its interference in breathing and may rarely progress to cancer. The figures of infection with HPV are alarming with about 20 million currently infected with HPV and about 50% of sexually active men and women are infected with genital HPV at some point during their life time.
About 80% women would have acquired HPV infection by 50 years of their age and approximately 6. 2 million Americans acquire new genital HPV infection every year. HPV lives in the skin or mucous membranes causing no symptoms though some people exhibit genital warts, very rarely HPV infections result into anal or genital cancers. Genital warts are soft, moist, and pink or flesh colored swellings and cauliflower shaped in the genital area. Genital warts can be detected by visual inspection.
“Pap” smear test or Papanicolaou screening is an effective tool in detecting cervical cancer. Depending on size and location of genital warts the health care provider may offer one of the following ways of treatment: 1. Imiquimod cream 2. 20 percent podophyllin antimitotic solution 3. 0. 5 percent podofilox solution 4. 5 percent 5-fluorouracil cream 5. Trichloroacetic acid (TCA) Pregnant women are advised not to use podophyllin or podofilox and 5-fluorouracil cream. A health care provider may alternatively also remove the smaller warts by i.
Freezing (cryosurgery) ii. Burning (electrocautery) iii. Laser treatment. Concluding I would like to state that the greatest risk of HPV infection is cervical cancer which may complicate in case of pregnant women leading to difficulties in delivery due to the obstruction caused by warts in the passage of baby at the time of delivery. Rarely babies born to women with genital warts develop warts in their throats i. e. , respiratory papillomatosis which may be life threatening.
References Human papillomavirus. Wikipedia, the free encyclopedia (2006). Retrieved on http://en.wikipedia.org/wiki/Human_papillomavirus