The cortisone injection made a radical difference to my coeliacs ...I thought I only had lactose intolerance and a sensitivity to oils..but after the second injection within a month felt extremely unwell and had a strange rash on my elbows. Thought it was caused by deadly nightshade after I dug up a grape vine.
Long story short ..eventually saw my French GP who hadn't a clue...did an extensive search on the Internet and the blisters are pretty unique to the intolerance.
Last six months have followed diet strictly but have had half a dozen "incidents" - mostly eating out (and not being told the truth) and once when I ate just four pringles crisps...just made the loo.
Actually feel much healthier now I know what it is and can control it.