I had severe itching with each PPI that I tried and antihistamine didn't help either. I already have eczema and the ppis seem to aggravate it. I eventually found - by accident - that taking a little raw olive oil calmed my skin enough to cope with the ppi. I did some in depth thinking and digging around at the time and had these thoughts:-
1) ppis are proven to increase food allergy as you cannot digest protein as efficiently whilst taking them
2) ppis in capsules come in a variety of colours - may be I was allergic to the colourings. I switched to Lansoprazole which is white capsules
3) it may be nothing to do with allergy and may be a more typical drug reaction - sometimes with those you can become tolerant over time, but of course you may not
4) there may be a lower dose at which you can get some benefit but no side effect
Have you asked to be referred to an allergy consultant? I think I may have posted to you before about the research showing milk allergy as a cause of acid reflux in children....?
New stuff: GERD, Recurrent cystitis/Overactive bladder
Lifelong stuff: Food allergies/intolerance, eczema, asthma