A 42-year-old man has had a constant bad taste in his mouth for the past month. On physical examination there are white fluffy patches on the sides of his tongue. These cannot be scraped off. A biopsy is taken and on microscopic examination shows squamous epithelial hyperkeratosis, parakeratosis, and koilocytosis. Immunohistochemical staining for Epstein- Barr virus (EBV) is positive. Which of the following is the most likely risk factor for his oral lesions?

Oral hairy leukoplakia is seen in immunocompromised persons. It presages AIDS in persons who are HIV positive. Chronic alcohol and/or tobacco use are associated with oral squamous cell carcinomas. Type 1 diabetes mellitus with ketoacidosis is associated with fungal sinusitis, particularly with mucormycosis. Pernicious anemia from vitamin B12 deficiency is associated with glossitis that is mainly atrophic. Sjogren syndrome leads to inflammation and atrophy of salivary glands leading to xerostomia with atrophy, fissuring, and ulcerations in the oral cavity mucosa.