Kindly give your expert opinions on management of multiple large painful apthous ulcers. The patient, a young male, was undergoing dental treatment and was on amoxicillin and clavulanate potassium for 3 days, after which he developed oral ulcers.

He is unable to open his mouth for talking, without fever, not responding to conventional treatment of vitamins, oral rinse, and NSAIDS since last 8 days.