bullous lichen planus

If canker sores persist or continue to return, tests should be done to look for other causes, such as erythema multiforme, drug allergies, herpes infection, and bullous lichen planus.

Bullous lichen planus (also known as "Vesiculobullous lichen planus") is a rare variant of lichen planus, characterized by the development of vesicles and bullae with the skin lesions.