Hairy leukoplakia: an AIDS-associated opportunistic infection.

Hairy leukoplakia has been defined and confirmed as a specific oral mucosal marker for human immunodeficiency virus infection. Light microscopic findings include alteration of spinous layer cells, which contain nuclear chromatin abnormalities. Enlargement of spinous cells with ballooning degeneration is also characteristic. Ultrastructural morphology has defined the presence of large numbers of herpes-type virus particles within the intranuclear, cytoplasmic, and intercellular regions. Morphologically, the criteria of Epstein-Barr virus are satisfied. Southern blot analysis has confirmed the virus to be Epstein-Barr virus. Further hybridization analyses failed to show any evidence of human immunodeficiency virus or human papillomavirus in the lesions themselves. We conclude that hairy leukoplakia may represent an epithelial opportunistic Epstein-Barr virus infection. Finally, the production and shedding of Epstein-Barr virions into the oral cavity from the sites of hairy leukoplakia can occur separate from the usual tonsillar and oropharyngeal sites.