<unk>  is caused by human papillomavirus (HPV) infection, most frequently types 6 and 11 although genotypes 16, 18, 31, and 33 have also been implicated. HPV-11 is associated with more aggressive forms of<unk> , which may involve more distal parts of the tracheobronchial tree. The mode of viral inoculation is hypothesized to vary according to age of disease onset. The presence of HPV in the respiratory tract does not necessarily result in the development of<unk> . Other factors that could be involved include immunodeficiency or other similar infections. For example,<unk>  may become more aggressive due to the presence of certain viruses (e.g., herpes simplex virus, Epstein–Barr virus). The disease occurs in two forms, juvenile and adult<unk> , based on whether it develops before or after 20 years of age. The juvenile form is generally transmitted through contact with a mother's infected vaginal canal during childbirth. Less is known about transmission in the adult form of this disease, though oral sex has been implicated as a potential mode of transmission. However, it is uncertain whether oral sex would directly transmit the virus or activate the dormant virus that was transmitted at childbirth. In general, physicians are unsure why only certain people who have been exposed to the HPV types implicated in the disease develop<unk> . In the case of the juvenile form of the disease, the likelihood of a child born of an infected mother developing<unk>  is low (between 1 in 231 to 1 in 400), even if the mother's infection is active. Risk factors for a higher likelihood of transmission at childbirth include the first birth, vaginal birth, and teenaged mother. Three major risk factors affect the acquisition of the juvenile variant. These include: * Birth history (e.g., increased time spent in vaginal delivery) and the presence of HPV in the vaginal canal. It is important to note that it is still uncertain whether caesarean delivery is a protective factor. * Genotype of the HPV (e.g., HPV-11) * Individual factors (e.g., being younger when diagnosed, which may be due to a less developed immune system).
Laryngeal papillomatosis
Laryngeal cyst
Otic polyp
Oral mucocele
Nasopharyngeal cyst
Epiglottitis
Vulvitis
Tuberculous gumma