Question: My upper lip has been swollen and a little numb for three months. At times it is worse than others but it never completely goes away. My gums, lips and tongue are also very easily irritated. I do not have any sores. I also find that I am not making as much saliva and need to sometimes clear food with water. I have been to my regualr doctor, an endochronoligist, my dentist and to an allergist where I was tested for allergies. What are other possible causes? I'm starting to get nervous.

Thank you for your response. To answer your follow up questions:
a. When I intially woke up three months ago and my lip was swollen I was very nervous about it. I went to the doctor in the first 24 hours because it had come on so quickly and I intially thought I was experiencing some sort of allergic reaction. In general, I am not anxious or nervous. As a matter of fact, it is my family and friends around me who feel I need to be more agressive in seeking a diagnosis since it has been over three months and it continues. I thought it would pass as mysteriously as it appeared - but it is not.
b. I have not undergone any surgery and I currently take no medication where I am (other than this) in very good health.
c. My lips feel very weird and it does interfere with both chewing and sometimes speaking. My gums hurt and I feel as if I don't chew carefully and avoid sharp food (like toast) or I feel as if my lips and gums have been scratched up. I also find it odd that I know seem to have a lot of food and debris left in my teeth and gums after eating and need to brush or swish water in my mouth right away to clear. Although I do not feel like my mouth is dry other than that and my eyes are not dry at all either.
d. My doctor has done extensive testing and except for slightly elevated sugar levels all seem fine and within normal limits.
e. My eyes are not dry at all.
f. I was eating a banana every morning in my cereal but I sopped that about a month ago thinking I should try eliminating things in my diet. I always eat a healthy salad for lunch and generally have at least two servings of vegetables with my dinner. I cut out orange juice (which I used to drink 2-3 times a week because I thought the acid might be bothering me.
Its very strange and as I said, there are times my upper lip is so swollen I can't close my lips (more so in the morning) and other times its barely swollen but I always feel as if I ate too many salty pototoe chips, even though I rearely or ever eat salty snacks. My next step is to go to a rheumatoligist then a ENT.