Hi. Welcome to Healthcaremagic. I read your query. In tongue there are naturally larger taste buds at the back of tongue as compared to front. Also, there is lingual papillaem As you mentioned you have an infection, chances are it could be an enlarged taste bud or papillae due to infection, medication or some allergy. It can also be an ulcer. Normally these happens with fever and infection and regress on their own. I suggest you to check if it is discoloured, enlarge or have uneven borders, then get it checked. Else you can wait for healing up of your infection. Take your prescribed medications. Take multivitamin tablet one per day. Maintain gud oral hygiene. If warm water is tolerated, do warm saline rinses. Maintain good diet and hydration. If it burns while eating, you can apply oral anesthetic gel 5 min before eating. Hope the answer helps you. Thank you!