Detection of human papillomavirus type 56 DNA, belonging to a mucous high-risk group, in hair follicles in the genital area of a woman no longer suffering from viral warts

Background Human papillomaviruses (HPVs) parasitize human epithelium, but it is not clear where they reside when they do not cause apparent infection. Hair follicles are important candidates as reservoirs. Objectives A patient reported previously by us as having perianal warts caused mainly by HPV 56, demonstrated hair follicles in her genital area which bulged a little from the surface and appeared somewhat enlarged. We therefore examined whether DNA of HPV 56, a member of the mucous high-risk group, might be detectable in these structures. Methods We obtained plucked hairs and performed an examination by polymerase chain reaction and subsequent reverse-phase dot blot hybridization (PCR-RDBH) and in situ hybridization (ISH). Results Strong positive signals were obtained not only with PCR-RDBH but also with ISH. Conclusions Hair follicles in the genital area might serve as reservoirs for HPVs belonging to the mucous high-risk group.