Introduction: Recurrent respiratory papillomatosis (RRP) is characterized by the presence of benign virally induced tumors of the larynx and respiratory epithelium that may obstruct the airway and tend to recur frequently. RRP is caused by the human papilloma virus (HPV), most frequently by HPV types 6 and 11. In this study, we present four cases of children with RRP in whom HPVs other than HPV-6 or HPV-11 were found.
Material and methods: In all four cases, HPV typing was performed by polymerase chain reaction (PCR) followed by restriction digestion (RFLP) in biopsy samples collected during surgery.
Results: In the first case, simultaneous HPV infection with types 13 and 39 was detected, while in the second case HPV-40 and HPV-56 were found. In cases 3 and 4, the biopsy samples were positive for unidentified 'low-risk' HPVs.
Conclusions: The presence of novel HPV genotypes in children with RRP emphasizes the need for further investigation of the implication of these genotypes in the disease.