I've been suffering from food allergies for many many years. I've not been able to find any pattern to them until now. I've just figured in the last couple of days that all the foods I react to have a moderate to high nickel content. I've often thought I was going crazy.
Two years ago I had severe swelling of the tongue where I was close to stopping breathing and had to be rushed to hospital. The reaction started after eating prawns. I had had a few mouth ulcers and blood blisters with prawns, but not each time so I was caught unawares. The nickel content of those prawns must have been very high.
I develop hives and severe itching as well as rashes when I consume all the usual nickel suspects (chocolate, nuts, green leafy veg, potatoes, wholemeal grains, lettuce, some fruits, peas, lentils, onions, garlic. Oh my the list is endless it seems).
I stay better when I eat meat, poultry and dairy produce. Not so clever on the fibre that. I've read that sweet corn (maize in the US? (I'm writing from the UK)) is OK for nickel so have started to eat that. Thank you for the tip re cilantro. I will try that too.
For the anaphlaxis I now carry epipens (ie adrenaline for self injection) should my tongue swell again.
About a year ago I started getting lower back pain which no-one can figure at all. They reckon it may be psychosomatic. It's like fibromyalgia, I think. I find sitting for any length of time quite unbearable. It has had a devastating impact on my life but somehow I've figured a way of coping.
This last year I had been trying to eat more foods. As I had no idea about nickel I was trying bread, potatoes, chocolate, peas, lentils. Oh my! Anway I got severe pain in my fingers which my doctor could not understand. I mentioned allergies and he laughed. I felt a bit silly. I gave up some of the foods that made me itch a lot, but kept trying others. Then my lower back went.
And the gut bloating (had this for ages too) got worse and life seemed quite hellish.
Recently my right arm started to hurt, and the taste of food seems very odd. My heart rate is sky high (85-100) and my blood pressure is 130/100 ish.
I've stopped all that trying different foods and have reverted back to my old old rather tedious diet, but I'll add the corn and see what happens.

Sorry such a long post, but it's great to have found this forum.