[Oral focal epithelial hyperplasia. Any risk of confusion with oral condylomas?]

Focal epithelial hyperplasia (FEH) is a disease of the oral mucosa caused by human papilloma virus (HPV) types 13 and 32. It is not very common in Denmark and thus not well known to most physicians. It is rarely seen in Caucasians, but in other parts of the world, especially in the southeast Mediterranean countries, among the native Indians of South and Central America, and in Eskimos the disease is rather common. FEH presents with exophytic lesions of the oral mucosa and may be rather easily confused with papillomas or condylomas, and therefore perhaps give rise to the suspicion of sexual abuse in children. We describe easy ways of making an accurate diagnosis of FEH and other HPV-related diseases.

We present five patients who were diagnosed with FEH by in situ hybridisation on biopsies or by conducting PCR with HPV type-specific consensus primers followed by analysis of the restriction fragment length polymorphism.

FEH could be diagnosed in all five patients by the two procedures described. In three cases, both methods were applied and gave identical results. Three patients were infected with HPV type 32 and two patients with HPV type 13. Co-infection with more than one HPV type was not found.

Many physicians rarely encounter FEH, and will thus have difficulty in reaching an accurate diagnosis. In doubtful cases, oral papillomatous or exophytic lesions should be subjected to HPV typing. When suspicion of oral condylomas is raised, particularly in children, accurate diagnosis is necessary to rule out suspected sexual abuse. Viral DNA for HPV typing can be easily obtained, simply by scraping the lesion.