A patient reports a recurring ulcer on the lateral tongue that appears where they repeatedly bite the area and heals when the biting stops. The most likely diagnosis is:

An ulcer that recurs at a site of mechanical trauma (tongue or cheek biting, a sharp cusp) and resolves when the irritant is removed is a traumatic ulcer. It should heal within about 2 weeks once the cause is removed; failure to heal warrants biopsy to rule out malignancy.Other options: SCC is a non-healing indurated ulcer; aphthae are not tied to a specific bite site and occur on non-keratinized mucosa; herpetic gingivostomatitis is a primary viral illness with multiple vesicles and systemic signs.Key exam takeaway: An ulcer tied to a biting habit that heals when trauma stops is traumatic; any ulcer not healing in 2 weeks needs biopsy.