A 42-year-old man presents to the clinic complaining of a sore mouth and an unpleasant taste for one week. He finds it uncomfortable to eat. His medical history is significant for human immunodeficiency virus (HIV) infection diagnosed five years ago. He admits to poor adherence with his highly active antiretroviral therapy (HAART) over the past year. He has experienced similar oral symptoms on several previous occasions. These were treated with topical lozenges, but he does not recall the name. He has a 10 pack-year smoking history but denies alcohol or recreational drug use.