Human Papillomavirus (HPV) is a common group of viruses. Over 200 types of HPV have been identified, with some causing skin warts on various body parts, while others affect mucosal surfaces like the genitals or mouth. HPV types are categorized as either “low-risk” or “high-risk” based on their potential to cause cancer. HPV types 6 and 11 are classified as low-risk types, meaning they are rarely associated with the development of cancer.
Conditions Caused by HPV 6 and 11
HPV types 6 and 11 are primarily responsible for causing benign conditions, notably genital warts and recurrent respiratory papillomatosis (RRP). These low-risk HPV types account for approximately 90% of all genital wart cases.
Genital warts are soft, flesh-colored growths that can appear on or around the genitals, anus, or groin. They can vary in size and shape, from small, flat lesions to cauliflower-like clusters. While generally not painful, they may cause itching, redness, or discomfort in some individuals.
Recurrent Respiratory Papillomatosis (RRP) is a less common but more serious condition caused by HPV 6 and 11, where wart-like growths develop in the respiratory tract. These papillomas most frequently occur in the larynx, or voice box, leading to symptoms such as hoarseness, voice changes, or difficulty breathing. RRP can affect both children (juvenile-onset RRP) and adults (adult-onset RRP), with juvenile-onset cases often being more aggressive and prone to recurrence.
Transmission and Prevention
HPV types 6 and 11 are primarily transmitted through intimate skin-to-skin contact, most commonly during sexual activity. The virus can spread even when an infected person shows no visible symptoms. While less common, vertical transmission from a mother to her infant during childbirth can occur, which is a recognized cause of juvenile-onset RRP.
Vaccination offers significant protection against HPV 6 and 11. The Gardasil 9 vaccine, for instance, protects against these two low-risk types, along with several high-risk types associated with cancer. Routine HPV vaccination is recommended for individuals starting at age 9, with a typical recommendation for those aged 11 or 12, ideally before sexual activity begins. For individuals who start the vaccine series later, between ages 15 and 26, a three-dose schedule is usually advised, while those younger than 15 can often receive two doses.
Using condoms can reduce the risk of HPV transmission, but they do not offer complete protection because the virus can be present on skin areas not covered by the condom. HPV is transmitted through skin-to-skin contact, not solely through bodily fluids. Limiting the number of sexual partners can also help lower the risk of exposure to HPV.
Diagnosis and Management
Diagnosing conditions caused by HPV 6 and 11 often begins with a visual assessment. For genital warts, a healthcare provider can usually identify them through a physical examination. A biopsy, where a small tissue sample is taken for microscopic examination, may be performed if the diagnosis is uncertain or if the warts appear unusual.
Diagnosing recurrent respiratory papillomatosis (RRP) requires specialized procedures. An ear, nose, and throat (ENT) specialist may perform a laryngoscopy, which involves using an endoscope to visualize the vocal cords and respiratory tract for wart-like growths. If lesions are located deeper in the airways, a bronchoscopy may be necessary to confirm the diagnosis.
Management of these conditions focuses on treating the visible symptoms, as there is currently no cure for the HPV virus itself, though the body’s immune system often clears the virus over time. For genital warts, common treatments include topical medications such as imiquimod cream or podofilox solution, which patients can apply themselves. Clinician-administered treatments include cryotherapy (freezing the warts), surgical excision, or laser treatment. Recurrence of genital warts is common after treatment since the virus remains in the body. For RRP, treatment primarily involves surgical removal of the papillomas, often requiring repeated procedures due to the recurrent nature of the growths.