I have heard this before. A dermatologist told me it may be a negative reaction to the glycerin and that you shouldn't worry about it unless irritation occurs or if the burning becomes unbearable.
If that happens, you'll just have to start using barbasol instead!
If it does persist or becomes unbearable, you could try williams instead, it does have SOME glycerin in it but is based more in sodium tallowate.
For awhile I had this problem with mama bear soaps, but it wasn't enough pain to keep me from using it and there was no visible irritation.
On the other hand, maybe you had a cold sore forming that you just couldn't see yet!!!
Hope this helps, if not, PM me and I can try to find the dermatologist information pamphlets and mail them to you. Do note that I said TRY
