Oral hairy leukoplakia--10 years on

Oral hairy leukoplakia (OHL) was first observed in 1981 and reported in 1984. Initially, this entity was restricted to HIV-seropositive male homosexual patients, but the risk group has been expanded since 1986 to all patients infected with HIV. It has been recognized that OHL is caused by Epstein-Barr virus (EBV). In 1988 we reported the first HIV-negative immunosuppressed patient with documented EBV-positive OHL. In patients with OHL, continuous shedding of EBV from saliva is necessary to maintain the lesion. EBV shedding leads to repeated infection of the intraoral epithelium. This may explain the highly variable course of OHL. The lesions may spontaneously disappear within few days. No latent EBV can be found in basal or suprabasal cells. In OHL coinfection with multiple strains of replicating EBV was documented recently. The clinical diagnosis of OHL may be confirmed by ultrastructural examination or in situ hybridization of exfoliative cytologic specimens. OHL is highly predictive for the development of AIDS. However, in HIV-seropositive patients, detection of EBV-DNA in the oral epithelium by the scraping method may be an earlier and more powerful predictor of progression to AIDS than is OHL.