Also to answer your question, do we think that the crusty lips could be somehow caused by the mercury-silver dental amalgam fillings? None of us on this healthboard can say for sure. Metal allergies are being researched all the time by scientists throughout the world.
I hope that you are seeing a good doctor to help you. All we can do is point out some good information, which may help you work with your medical professional in finding out more of what is causing your lip problems.
Here's one URL you might want to look at: http://www.melisa.org/nialler.pdf
I didn't have time to read it thoroughly. I neither support or disagree with the reading. It's just seemed quite interesting. Apparently some people are painfully allergic to nickel as well as to mercury. In another source, I saw a picture of person with a swollen neck that apparently was caused by nickel in a necklace and another picture of someone's hand swollen in response to nickel allergens. Nickel is in many metal products that we use daily in our household.
It looks like each of us, has a different level of sensitivity to these metals too. It's good that some medical professionals are recognizing this. If your doctor suspects that your dental amalgam fillings are giving you problems, please let me know if you have any other questions. I'd be glad to help.
Also, I would think that your lip problems could be caused by a virus too, but I'm assuming that you already have reviewed that with your doctor. What makes you question your dental fillings? Have you not been able to find out what is causing this problem?