<s>[INST] Hi, What are the symptoms of a human parastic infection on the tongue? For example, the patient has had a half-an-inch wide white mouth ulcer near the tip of his tongue, which has caused him much irritation and occasional pain for most of the last three years. It has never really gone away, but has not spread to any other part of the tongue or mouth. Yeast pills, acyclovir , and mouth washes have not had any affect on it. Nor has peroxide , which seems to make it all the more irritated. Since it has been on his tongue for over three years now, baffling doctors (except for the latest physician who did a biopsy and is awaiting the results) do you think it could be some sort of parastic infection. Or does it seem more like the precursor to, say. mouth cancer or such? Any info would be greatly appreciated. [/INST] hi as per date there has been no such information on any parasite infecting the human tongue. and as the lesion is painful and is appearing elsewhere in mouth also indicates the non malignant nature of the lesion . what seems like in this case is the condition called recurrent apthus ulcers. the best way to  subside the symptoms is to drink good amount of water to drink and application of protective film producing oral gel. once the diagnosis is confirmed the patient can be given instructions regarding food pattern and multivitamins course. wishing quick recovery for the patient , take care. </s>