Different papillomaviruses as the causes of oral warts.

We have observed four patients with oral papillomas. Two children had oral mucosal lesions characteristic of focal epithelial hyperplasia, a young man had common, wart-like lesions on his hard palate, and a male immunosuppressed renal allograft recipient had condyloma-like lesions on his gingivae. Papillomavirus-like particles were seen by electron microscopy in lesions from both patients with focal epithelial hyperplasia. No structural antigens for human papillomavirus (HPV) 1, 2, 3, or 5 were found by immunofluorescent microscopy, but further evidence of the presence of a papillomavirus was found by immunoperoxidase microscopy using a cross-reacting sodium lauryl sulfate-disrupted bovine papillomavirus 1 anti-rabbit serum sample. The distinct histologic pattern seen in focal epithelial hyperplasia suggests that a yet undescribed HPV type might be associated with this disease. Histologic, ultrastructural, and immunofluorescent microscopy and restriction endonuclease analysis all gave evidence of HPV 2 in the palatal lesions in patient 3. Evidence of papillomavirus antigen was found by immunoperoxidase microscopy in the oral condylomas from our immunosuppressed patient.