You become more sensitive to the poison
the more you are exposed. It's very bad advice to tell someone you won't have
a reaction next time. How the hell do you know?
This is true and false... For example some woods have a allergens in the dust, you can work with the wood one day and have no reaction. But after a week your body has been 'sensitized' and you can have a full blown reaction with itchy hives and edema. I know, I've been there. But after taking a break and coming back later and doing the same work the reaction gets less and less. My tolerance now is very high for these dusts, usually only causing 1-2 small itchy pimples, which I ignore and they go away without treatment. This is desensitization in long term
This also applies to mosquito bites, my edema or for allergies they call oedema (welts) reduce in size. I've seen remarkable tolerance to fire ant bites in myself, they don't even cause raised pimples or any itching anymore. I knock them off and only experience mild itching. When I was young they would caused raised pimplish welts my mother would drain with a needle.
I'm pretty sure my reaction this time was because this was my body's first encounter with yellowjacket antigen, and I got stung very good twice. I think the sting released more poison because the yellowjacket stung through my sunsleeves and maybe released it's full load or stinger got stuck.
Even my ER doctor said that next time I may or may not have a reaction, but to be safe carry the epinephrine shots with me, and if I have to use them come to ER for followup. Since these only work 20 minutes (or for me about 2 hours in the ER I felt effects).
So yes desensitization is a thing for long term.. and also sensitization is also a thing for short term. That is why doctors do the antigen tolerance therapy, giving small doses over time, just like a snake handler drinks poison, or how alcoholics can handle a full liter of whisky.
In the article I cited they also talk about this:
Natural course
A substantial proportion of patients (20-80% in different studies) with a history of a generalised reaction to a sting have no such reaction to a subsequent sting—that is, spontaneous improvement is common
Less severe generalised reactions may also occur
However, the course can be variable—a series of stings may result in a generalised reaction, no reaction, and then another generalised reaction
Children do particularly well: one study showed that 95% of those with a history of mild generalised reactions had no reaction to a subsequent sting
The next sting will not necessarily cause a more severe reaction, but patients in accident and emergency departments are often told that it will
Reasons for the variable outcome are not well understood but include the interval from the last sting (the longer the interval the lower the risk of another generalised reaction), the patient’s immune response at the time of the sting (this will change with time), the dose of venom injected, and the site of the stingSo yes, a subsequent reaction is entirely possible, and a subsequent non-reaction is entirely possible too, but there is no guarantee of either, and for my case I'll definitely go fill my prescription of epinephrine. Sad part is I read they have to be at about 75 degrees storage temp, so I'll have to keep at home, keeping in car would be best.
I would suggest for your condition to try to get prescribed epinephrine shots, epinephrine is adrenaline, it is not proprietary, and you do not have to buy overpriced 'epi-pens'