It is certainly difficult. My own internist just had a CME in this about a year ago. And most diagnositic sites on the net mention 1972 as a turning point in diagnosis.

I had the GI spells all thru childhood, and they were most awful in my twenties. I developed some "asthma" in my 40's.

Antihistamines don't work well for me or at all. I've had facial swelling and tongue, with breathing SOB on and off with that ACE inhibitor. My left ankle swells and goes down willy nilly and my hands swell when I type alot.

There are some OTC things that do block bradykinin receptors.

One is bromelain extract...which should be enteric coated for use for systemic effects. The uncoated type is degraded by stomach acid since it is an enzyme. I only found one brand and that is LEF... which I buy on Amazon now. Also mentioned was Green Tea, so now I am drinking that. Polyphenols in general are mentioned to be helpful...so whatever you want to do with that is up to you. Certain foods will trigger me. Fresh fruit, esp oranges will set me up for an attack. So does coffee.

Most of my attacks are GI ... last about 3 days, and come at least once a month, and if I am unlucky twice a month. I use imodium and Librax for them, which works pretty well.
I have had serious attacks following invasive procedures, including dental work. Needles will also cause swelling, and that started when I was around 10 yrs old when "penicillin shots" were common. I've had my whole arm swell up twice as big with any injection. Bug bites! I ended up in the hospital with a black fly bite on my eyelid, which swelled my eye shut and face swollen! I overreact to mosquito bites too.

Medical treatment is ferociously expensive if you get one of the new drugs listed at the HAE site. One of them I got a quote from CVS for $10,000 for one injection! . However the androgen treatment, esp the priming before surgeries etc looks promising, since it is less expensive. Not a great thing to look forward to for women however, as facial hair, acne and weight gain may happen with those androgens! It would be something to discuss with the immunologist. I see some positive effects with the Bromelain.
I might increase to 2x 500mg a day. Avoiding the triggers is hardest for me. When I feel good, I am tempted to have some fruit...then bingo... another attack. I had a huge attack last week from some nice oranges! DANG...

When I have the green tea (a huge mug) + Bromelain, my hands don't swell so much. I think alot of it is trial and error, depending on the person.

When I get my testing which might not be until after our summer vacation, I'll PM you with the results. I am still recovering from the lisinopril (which also caused a lupus reaction for me)...so I am not going to go for the HAE...yet. I have to see what was causing what..exactly.