Hi..
Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concern..
As per your complain a painful red spot over the tongue can be an apthous ulcer or a
canker sore and it can be due to a number of causes and side effect of any medication can be a potent cause.
Other causes can be deficiency of iron and
vitamin B12,
stress,
acid reflux, physical trauma etc..
I would suggest you to consult an Oral Physician and get evaluated and a thorough clinical evaluation along with investigations as per suspected cause can help in diagnosis and treatment can be advised accordingly..
As of now he can apply a numbing gel containing Lignocaine over the painful area..
He can do warm saline gargles..
Cool compresses over the spot and cold water rinses can relieve..
Tylenol can be taken for reducing pain..
Take soft and bland foods and avoid spicy and citrus foods..
Hope this information helps..
Thanks and regards.
Dr.Honey Nandwani Arora..