I developed a canker sore last Tuesday. It is located right under my lip on right side. Normally I can get rid of a canker sore within 48 hours using Lysine Tables, Topical Lysine (yes I apply it internally) and Salt Water Rinses. However, I am not having any luck this time. I have also noticed that my gums are itching in between my teeth (mostly in between my two teeth behind my sore). Actually my entire mouth feels a bit itchy. There is no bleeding when I pick in between my teeth. In addition, I'm notice that the top right part of my lip is partially numb. I don't notice any terrible odor. Some things to take into account are that my immune system may be compromised at this time due to the fact that I was taking Benadryl couple weeks ago for Poison Ivy (never doing that again). I also recently began taking Levothyroxine for my thyroid condition and my thyroid may still be underactive. Up until early last week, I had been drinking very diluted orange juice as my vitamin mix base but I decided that was too acidic. I had also been consuming lots of strawberries. And vinegar on my salad. As you can see, I'm minimizing my acidic food intake. Any help would be greatly appreciated.