I have a reaction to intimate lubes
that contain glycerin. I am not "allergic" to it. Allergy implies that a histamine reaction is going on and that isn't the problem with me. I can use other products on other parts of my body containing glycerin and NOT get a reaction, but if I use it on my genitals I get vaginal infections and UTIs.
So, it's a reaction, but not a true allergy. Believe me I have plenty of true allergies, and they are not the same as simply being sensitive to an ingredient.
I avoid glycerin in lubes completely. But, I have plenty of hand creams, shampoos and conditioners, hair stuff, etc that contains glycerin and it works well and doesn't cause a problem with me in any other part of my body other than my genitalia.