The most commonly documented causes of anaphylaxis are:

Food (Peanuts, tree nuts (walnuts, pecans, etc. Shellfish, Fish, Milk, Soy, Wheat, Eggs)
Medications (Penicillin, Sulfa antibiotics)
Insect venom (Bees, Wasps, Yellow jackets, Hornets, Ants, especially the fire ant)
Latex (Gloves, Balloons, Condoms)
Exercise

See www.allergic-reactions.com/home/causes_main.html

No mention of plants. I got a horrible attack of itching, swelling, etc, that went on for days after squeezing through a privot hedge in Worthing.

Is there much fresh fruit about? Maybe you should go on a plain rice and fresh fruit diet. They say it’s usually what you crave that you’re allergic to. Noodle soup, mayhap?

Apis is the best homeopathic remedy. Have you got any?

I reckon it’s something to do with Thailand. Something you’re eating, drinking, touching, being bitten by, anointing yourself with – soap, perfume, insect repellent – that wasn’t happening in India or Vietnam or Cambodia or Laos. Get out of Thailand, I say!