Hello, You may have an allergic type reaction or an infection of the soft tissue of the mouth. The onset of a throat infection such as strep can have this reaction. Breathing by mouth can cause a dry mouth and lips. This is a stress on your tissues and causes discomfort. First think of any changes to products used, medications or in your diet. Stop the use and evaluate. Take some anti-inflammatory medication such as acetaminophen and ibuprofen. Benedryl is an antihistamine that can reduce inflammation and swelling. Rinsing your mouth with warm salt water, keeping well hydrated, proper nutrition and continued good oral hygiene are recommended. Avoid acidic foods and liquids. Alcohol use can cause dehydration. Drink plenty of water. Oral yeast infections can occur if you have recently taken an antibiotic or another medication that causes an imbalance in your natural bacteria. Lichen planus is an oral condition, often origin unknown, that can cause some of the symptoms described. Prescription antibiotics or comfort rinses could be recommended by your dentist. Schedule a dental visit for a clinical evaluation and review of your dental and overall health. Please seek immediate care if symptoms become worse or you feel the risk of anaphylaxis. If you have additional questions or provide more details, I will be glad to make additional suggestions. I hope my suggestions are helpful and thank you for your inquiry.