Welcome to HealthcareMagic. It can be leukoplakia
, lichen planus
or oral fungal infection( Thrush) if it can be scraped off. Thrush appears as white patches in the mouth. Usually they can be seen on the tongue, inside the cheeks, under the tongue, and in the back of the throat. I suggest you to get an examination done from your doctor and get a KOH examination of the scrapings done of these white coatings. Leukoplakia is a white lesion that can't be removed simply by rubbing the mucosal surface. It may occur in response to chronic irritation from dentures or from tobacco use or pipe smoking
, or it may represent dysplasia
You have to consult an oral surgeon or an ENT specialist
to get it evaluated. Hope it helps you. Regards.