A patient has small, oval multiple ulcers in the oral cavity with red erythematous margins. The diagnosis is

Aphthous ulcers They are painful, recurrent, superficial ulcers, usually involving movable mucosa, i.e. inner surfaces of lips buccal mucosa, tongue, the floor of the mouth and soft palate while sparing mucosa of the hard palate and gingival. It has 2 forms - minor & major In the minor form, which is more common, ulcers are 2-10 mm in size and multiple with a central necrotic area and a red halo. They heal in about 2 weeks without leaving a scar. In the major form, the ulcer is very big 2-4 cm in size, and heals with a scar, but is soon followed by another ulcer