All the Allergy Tests: For Asthma and Beyond

Back in September, my asthma specialist and I decided it was time to do allergy tests again. It had been 10 or 12 years since my last tests were done, and I have been having some symptoms at specific times that could be allergy related. My new allergist was fabulous and shared some insights I thought were really interesting and thought I would capture them here for others!

I have learned over the years that there is really no set interval for how often to do allergy tests. My family doctor told me about his patient whose girlfriend wanted to move in with her cat, and he requested testing to see if he was still allergic. Well if you are going to find out you are allergic to something and not be able to do anything about it anyways--i.e. the girlfriend and the cat were moving in regardless--it may not actually be that helpful!

Determining allergies: With asthma in the mix

Do I need allergy testing?

Similar to my doctor's anecdote, my allergist made some great points: we can pretty easily treat nose symptoms, but if it starts impacting your asthma, that becomes more of a problem.

I had not actually thought about this before, likely because I do not have a ton of allergic triggers--at least not that tests have identified, more on that in a second--but it makes sense.

Although I am sure miserable feeling, there are other potential treatments for environmental or pet allergies (ones that are mild or uncomfortable but not life-threatening). For instance, though it takes a long time and is not perfect, immunotherapy (allergy shots) can be looked at in addition to various nasal sprays, oral antihistamines, or topical steroids for skin reactions.

Now, this is not to say testing is not worthwhile: it very well could help you figure out what to do to keep your allergy symptoms at bay. But, if you are not actually able to avoid an environmental allergen, it is worth considering the necessity of the testing. Will it just cause more stress?

Not all allergy skin testing mixes are created the same?

When you have allergy skin testing done, a few drops of a solution containing the allergen (this would be the "mix" mentioned above!) are put onto your skin and then poked in with a lancet to penetrate the skin and then checked 15 minutes or so later to see if they trigger a reaction.

My skin tests have always been negative, well, except the first time when they thought nearly everything was positive but it appeared the control had not reacted properly and I had them re-done. My new allergist actually explained this phenomenon, too. It was likely something called dermatographism, where a light scratch to the skin can cause redness, which in the case of skin tests could appear like a mild allergic response to the test. Medicine ain't perfect.¹

Anyways, back to the testing solution. It turns out, multiple different companies make different allergy testing mixes. As my doctor told me, just because you do not react to the skin test...wait for it...does not mean you are not allergic to the allergen.

He told me in my case if he was able to, he would like to test me with 2 or 3 companies' versions of the same mixes and see if I responded differently. Alas, the province only buys one type and I am sure it is the same one they were buying a decade ago.

Now, I did not consider asking how much the vials of testing stuff cost and if he was able to order them, because I would be extremely curious to test out his hypothesis. That is on the list for the next time I see him, or, me being me, I would like to suggest we work on a proposal together for a little study of the hypothesis. I could be his first participant!

Not as straightforward as it should be

So, after all these years of just thinking I was not really allergic to stuff, which could still be true, my seasonal ebbs and flows in asthma could be absolutely due to other factors. It is interesting to learn that allergy testing is really not as straightforward as we might like to think.

The other thing he mentioned when reading my notes is that occasionally in doing food allergy testing people will test positive for things that cause no symptoms. So outside of severe, systemic reactions where they do not know what is causing them he does not like to just start doing food panels on people because sometimes they come back with multiple allergies to things that are not actually the problem they came in to solve, and that problem remains unsolved even after they have eliminated a ton of foods and feel no different.

I have had a lot more trouble wrapping my head around this one, and I still cannot fully make sense of it. For instance, however, I have pondered whether I could just not have skin reactions and be allergic to things--which is why blood testing exists despite its other imperfections, so, realistically, it would be reasonable the opposite would be true, that people are reactive but do have allergies?

It's all mind-boggling.

And the verdict is...

Overall, before I went in this time, I had felt skin testing for inhalant allergens was pretty straightforward, and always declared me pretty non-allergic to things. While my asthma sometimes follows a kind of allergic pattern of response to things seasonally, there are other potential non-allergic culprits in just about every situation. However, clearly, it is not quite that simple based on what my new allergist is saying!

So the verdict was... more tests, of course. I left my skin testing appointment and headed straight for the lab (well, once I figured out where it was!) to have my blood drawn and in a couple of weeks, I should have the results of the same panel done on my skin from how my blood reacts to the allergens.

Next up is contact dermatitis patch testing--which is all irritant-based, not allergen. And given I know at least my asthma is triggered by irritants like fragrances and cleaners, it will be interesting to see how that goes, and hopefully, some answers come of it. Even better if there's any applicability to my asthma.

Anyways. I am glad the allergist is the one to figure this stuff out, not me.