Last night Mrs. Duality was eating an avocado and experienced an itchy mouth and throat. Within a minute or two she had a largish (1 inch or 2.5cm) sore in her mouth rather like a popped blister. This morning she felt normal but still had the sore. I’m wondering what could be the cause, and if we should do anything about it. She has never before had such a reaction.
The avocado was from Walmart, if that matters. We still have one more avocado purchased at the same time.
When she cut it open it looked like a practically perfect avocado at the peak of ripeness. It tasted good.
She should go to an allergist and stay away from avocados until she’s sure she hasn’t developed an allergy to them.
She’s a nurse and she didn’t think it’s an allergy. No swelling, no hives.
Her reaction, minus the blister, sounds just like food related allergic reactions I’ve had, so I wouldn’t rule it out. Of course, I’m just someone on the internet, but just throwing the possibility out there.
Is she allergic to latex?
That sounds like some kind of anaphylactic reaction to me. Those are nothing to fool around with.
Here’s more information. The bullet point that is 8th from the bottom would be most relevant here.
What sort of nurse is she? That’s a textbook allergic reaction - and a dangerous one. She should see an allergist asap.
Another person with food allergy saying that this sounds like a textbook allergic reaction.
Get she to a board-certified allergist, stat!
No, there’s no time for that. Boil some water and get the sharpest fillet knife you have on hand. I’ll guide you step by step.
Sure sounds like oral allergy syndrome to me. From my powerpoint on food allergies, used to teach RNs and physicians:
Avoidance of trigger foods is key, along with judicious use of such antihistamines as diphenhydramine or others, and even rescue medication like epinephrine for life-threatening reactions.
Why’s it always a food allergy?
If she’s never had a reaction to an avocado before, might it be possible that the skin of the avocado had some sort of bacterial or chemical contaminant and when you cut into it, it spread to the flesh and she experienced a reaction to that?
Or perhaps not the avocado at all but something else she ate that night?
Occam’s razor. The simplest explanation that best fits the known facts is most likely correct.
OAS is well-known to do just what is described, very quickly.
There’s much less literature about that sort of reaction happening so quickly due to bacterial contamination, and while chemicals can certainly do that, it’s just not seen nearly as often as OAS.
The hypothesis about the cause can be revised as more information becomes available.
The only argument against allergy is by the victim, who states she knows it’s not that because she’s a nurse. Well, the only thing that can be more stubbornly wrong than a nurse is a doctor, so at the risk of being stubbornly wrong myself, I’m discounting that argument. 
“When you hear hoofbeats, think horses, not zebras. Unless you’re in Africa”.
So all my life I’m eating avocados without the slightest issues. And next time, bam! OAS?
No disrespect intended, doc. I value your opinion tremendously. But why not zebras, just once in a rare while to relieve the monotony?
Now you’re implying stuff that the OP didn’t mention, a high lifetime frequency of avocado consumption. So that complicates it. OAS is still a good working diagnosis for you too, but perhaps not as firmly. Even so, allergies can and do develop anytime in life, regardless of previous exposure frequency.
NM, effectively redundant
Is eating an avocado literally the only thing she did all day? Do you see how you’ve introduced a HUGE bias into the question by jumping to the conclusion that the reaction is linked to the avocado?
I’ve no doubt you see sudden onset of OAS far more frequently than I. Still, I’m inclined to look for deltas.
I’m tempted to have OP’s wife eat the other avocado (well washed). If not just to settle our differences but in the service of Science.
There’s a lot of ignorance and misconceptions about food allergies out there, but this is very close to the top of the list. Just because you’ve “always eaten” something does not mean you can’t develop an allergy to it. Far too often people have a reaction like the OP’s wife and shrug it off, not knowing that the next time they eat the food the reaction could be anaphylactic.
Not swelling or getting hives doesn’t mean you’re not allergic to something. I’m not saying this is the case here, but I’m allergic to avocados (amongst other things). All that happens to me is they make my throat itchy. No hives, no swelling, my throat doesn’t close up (thought it feels like it will, it won’t), but I’m still allergic to them.
(Yes, it’s OAS).
I hope you’re kidding. Otherwise this would be the most asinine post I’ve read in quite some time.