Hello, You have symptoms of a sore spot on the tongue which occurs due to an allergic reaction to prescribed medication leading to lingual papillitis. These occur when papillae become irritated and slightly swollen. Need not to worry. It generally doesn’t require treatment and clears up within two weeks. Do warm saline rinses two to three times a day. If the condition doesn t get better in a few days, then consult oral pathologist for proper checkup and rule out a condition like herpes or canker sore for pain and if you also have fever Tylenol can be taken. Maintain good oral hygiene and drink plenty of water. Coat the blisters well will antiviral ointment containing Acyclovir. Hope I have answered your query. Let me know if I can assist you further. Regards, Dr. Harry Maheshwari