Since I've been trying to cut out everything I'm allergic to, I figured that I ought to change my anti-histamines so that I move onto one that is safe.
Strangely I have not been able to find an over the counter anti-histamine in either tablet or liquid form that does not have some form of potential allergen in it.
All the tablets that I have looked at are lactose based. Of all the liquid anti-histamines I have looked at only one does not contain Citric Acid, instead the Piriton syrup contains methyl, ethyl and propyl hydrobenzoates (E214, E216 and E218) - known asthma triggers.
I would have thought that common sense would kick in somewhere in the pharmaceutical industry and that somebody would produced a hypo-allergenic anti-histamine!
Thankfully 
my milk allergy is to the proteins in milk not the sugars. This means that I am okay with the tablets. I'll be stuffed if I have to use the liquid anti-histamines though!
I can't tolerate either the sugars or the protiens so have to use the liquid form. I have to really fight not to nod off during our home ed studies!! I got blood tested with York labs, as did my son. Best thing we ever did, avoiding those foods has really helped. Rarely have to take the piriton now, but always carry it with me, just in case. One of my reactions is intensive fast acting itching all over, very embarrassing, especially when out and about!!!