 The principal study interventions will be dexamethasone 0.01 oral rinse or identical in appearance and taste placebo rinse. Additional allowed interventions will be standard oral topical analgesic rinse and acetaminophen on an as needed basis. Diagnostic and research evaluations will include complete history and oral and general physical examination, laboratory investigations, saliva collection, and oral mucosal biopsy. The interventional period of the trial will be 4 weeks. 