WakeUpMama, Good intuition to get that checked out now. You are exactly right about those 3 allergies going together, and I would advise you to be VERY careful in giving banana and avocado to your child. Since you are sensitive to them (if not exactly allergic), then your ds has been getting your antibodies to these things thru your milk (assuming you're BF?) and during gestation. Doesn't mean you shouldn't BF -- on the contrary!
To my knowledge I am not allergic to any of those things (altho a sensitivity to bandaid adhesive makes me worry about latex), so banana was my ds's first food at 5.5 mos. I knew he had excema and that allergies run in our family, but LLL recommends it as the first food and I had never HEARD of a banana allergy! Well sure enough, he reacted and has developed multiple food allergies ever since (he's 2.75 now). In my allergy research I have discovered that banana allergies in babies are VERY common and that bc they are difficult to digest (you know, you eat them when you have diarrhea cause they slow things down, right?), that they should NOT be the first food.
Sounds like your ds is doing fine with them so far, but since you have this tendancy yourself, I'd back off of them AND the avocado until he's older and his gut is more mature.
In terms of getting yourself tested, if you have insurance, you'll most likely need a referral to an allergist for either a skin-scratch test or a blood test (called a RAST). The jury is out on which is more effective. If you don't have insurance, go for whichever is cheaper!
And I agree, find out now, cause if you were ever hospitalized, it would be critical to know if you have a latex allergy.
Good luck with this. And let me know if I can be of any more help. Sadly, I know a good bit about children's food allergies . . . but hopefully that will never be an issue for your ds!