Allergy testing and not being able to get through the no antihistamine rule ?

[jschwab]

I feel like I read on here somewhere that someone else was unable to get through the skin prick testing protocol without antihistamines those last days. When I did the skin testing a few years ago, I thought I would have a little sniffliness and drowsiness but would basically be able to handle the three days required of no meds at all. Heck, I was going to even not take Benadryl for the week prior as per instructed and just ditch the Claritin for ten days and white knuckle it. Easy peasy, I thought. Turns out I had no idea going into it how bad my environmental allergies were or how dependent I was on on OTC antihistamines and I was even taking half a pill at that point (5mg). I'd been taking them like clockwork every 24 hours for 20 years straight, so I really just had no idea. I lasted 5 hours before I started mainlining Benadryl. If I recall, they had to alter the protocol in the end because I could not make it through those final three days where you are not supposed to take anything and I just said I would not do the test after all if I had to. Does that sound about right? Can they easily alter the protocol when they do the testing?

[CMdeux]

Nope-- if you really can't be off of antihistamines when they SPT, the results are probably not valid-- and you may well test negative to things that you ARE allergic to, is the problem.

Basing decisions on what is okay to challenge becomes really problematic in that case-- because if you challenge something that is an anaphylaxis trigger, you just (potentially) signed up for a hospital stay, tyvm.

Actually, my DD's last SPT results were attenuated in all probability because she needed diphenhydramine just 75 hours prior to skin testing.  Her histamine control was almost nonreactive.   She'd been off of cetirizine for 10 days... 

Egg was still plenty reactive... but this is why I'm a little gun-shy on challenging almond.  I'm just not so sure that I believe that one is truly negative.  Even if I did, meh-- it's just testing.  She tests non-allergic to milk, too, and we know that she is.  So.

We have about a 9 week window each year during which it is feasible to skin test my DD-- she can't be off of antihistamines that long any other time of the year.  It's more than a matter of inconvenience or discomfort for those with anaphylaxis Hx, actually-- because it lowers the threshold for triggering a systemic cascade significantly, btw.  At least that's the theoretical possibility.

[jschwab]

Yes, I got really freaked out when I realized how sensitive I was, in general, and the implications for both the food allergies but also in case of apocalypse - I realized I was completely dependent and not just taking them to function better, but to function at all. My environmental allergies are 100% controlled on Zyrtec or, alternately, Claritin (I switch off every seven years or so if one stops being as effective) plus nasal steroids unless I encounter something unusual like being in a place with a lot of mice or next to a freshly cut pine tree.  I do have to take them year-round, though. I literally took them every single day for 20 years before I tried that SPT protocol. Given that, I was stressed about the OFC the doctor wanted to do for milk with the same three day no meds protocol. I just could not imagine, as I was reacting very sensitively to milk at the time. I did not test positive for it at all, either. I did not test positive on the SPT for shellfish (my other food allergy), but did in the blood test. I think I may be less reactive to milk than I was before now, though, so I might be willing to take the chance to see if I can relax a bit. I think maybe I managed one day with no meds but I don't totally remember.

I didn't realize that challenges were so common. I had the impression then that they generally did not food challenge adults as they are unlikely to outgrow the allergy. Maybe I should reconsider it if the doctor suggests it. I'm getting ahead of myself, though, since I have not even seen the doctor yet and found out if she will just blow me off.

[Ciel]

My doctor suggested a food challenge for me a few years ago. Rather, he offered to 'feed me a peanut'. Um, no thanks. I would be willing to do an egg challenge though, based on my history with that allergen.

I agree with CM, that being off meds might be more dangerous than beneficial if helps prime you for a severe reaction.  In my experience, skin testing isn't accurate for everyone -- my histamine control is usually a tiny dot and nothing reacts more than a tiny dot or nothing. Unfortunately I know that I am allergic because of reaction history. However if an ice cube comes into contact with my bare skin it's instant mega-hives. It is frustrating to not have a solid 'yes' or 'no' instead of 'probably' or 'probably not'.

Good luck with whatever you decide!

[jschwab]

For the almonds, I already did my own food challenge because it was genuinely perplexing what had happened. The meal where I reacted was all food I normally ate, prepared by me in my own kitchen. Almonds were the most likely culprit as a new allergen since they are more likely to develop as an allergen. So, I ate an almond to test it. DO NOT TRY THIS AT HOME. I was still hopped up on the prednisone but I got pretty uncomfortable, took Benadryl and got through it without returning to the ER. Again, DO NOT TRY THIS AT HOME. I have no idea what would have happened if I had not still had the steroids in my system. I am personally satisfied I am highly allergic to almonds now (I ate them like candy up to late September). Breaking out in hives from almond oil in my skin lotion further confirmed it, then breaking out again pretty bad from eating something that was likely cross-contaminated with tree nuts (the manufacturer never wrote back to me to confirm). I feel I have my positive OFC, even if the skin and blood test are negative at the doc's. It would be nice to see about the dairy allergy though...

[jschwab]

My doctor suggested a food challenge for me a few years ago. Rather, he offered to 'feed me a peanut'.

That is nutty! I did trust the challenge the doctor proposed to me to some extent. It starts with waving the substance before your face, then touching, then trace amounts, up the line. That did not sound too bad. I was not comfortable doing it outside of a hospital setting, though.

[CMdeux]

Yeah, your doc definitely doesn't sound as crazy as Ciel's.   

I'd definitely try challenging dairy, though, if you have ANY reason to think that you might tolerate it baked/heated-- because that can be a way to keep your threshold dose high enough that you're unlikely to anaphylax from traces.  Given how hard dairy is to avoid completely, that's a pretty good idea, IMO.

[jschwab]

Yeah, your doc definitely doesn't sound as crazy as Ciel's.   

I'd definitely try challenging dairy, though, if you have ANY reason to think that you might tolerate it baked/heated-- because that can be a way to keep your threshold dose high enough that you're unlikely to anaphylax from traces.  Given how hard dairy is to avoid completely, that's a pretty good idea, IMO.

I actually have no reason to think that. I have more reason to think that I've become less sensitive to it since it had been so long since I'd had a reaction.