RE: Who knows what about "mast cells" "histamines" and "diet"?? I'm itching to know!
Oh boy. Just another thing we have in common Marilla. It gets mighty hot here in summer with high humidity too. I always loved summer, but dread it now as I have what I've been told is a 'heat allergy' ~ Not allergic to anything else, except heat ~ Which I find to be a bit weird.
My symptoms: Prickling like pins and needle, which comes if I'm outside in the heat, and more often than not, doing some sort of physical work, like gardening. This subsides as soon as I get out of the heat, but then the heat rash: Like little bites under the skin, intensely itchy and lasts then for days.
My 'heat allergy' may be different to yours ~ But this is what I've found out. Without the medical jargon: When you overheat, your body perspires (even if you don't notice it) and the perspiration is forming a layer on your skin, which is preventing the skin from breathing. So it helps to continually wash yourself down ~ Skin brushing, shower or just a rough flannel.
Our water and presume yours too is chlorinated. We now have a shower head that filters out the chlorine. But when we didn't, I would leave tap water in a large jar outside in the sun, so that the chlorine would evaporate and the water receives sun energy ~ Then use that to wash with.
Also you may be deficient in magnesium. Get the pure magnesium flakes and add them to (unchlorinated) water to make up magnesium oil. Have foot baths with it. Or rub into the soles of your feet.
There is a magnesium cream that I get here in Oz, made by an Aussie. But there are many on the market now. Just make sure you get a good one that doesn't have other chemical additives in it.
And there are natural anti-Inflammatories. The most popular is tumeric/curcumin. You can get this as capsules at a health food store. Also Quercetain ~ Also in capsules. You can take them together.
I've never had it, but a friend told me about curcumin oil which is the strongest form to take.
You can also use tumeric in your food and drinks. We can get the actual roots at our farmers' markets, but also use the powder. Tumeric requires black pepper to activate it.
This is what I do: Add a good teaspoon of tumeric to a cup of boiling water. Grind black peppers into it. Simmer for at least 10 mins. to activate. In a cup mix coconut cream and honey/maple syrup. Pour tumeric and black pepper liquid into it.
You can add other spices: beneficial ones are cinnamon, cardamon, cloves and (real) vanilla. I hope some of this may help.