Oh, blo, my heart goes out to you. I used to be called 'The Rash Queen' pre-SBD, had 6 full body rashes in the last 20 years, not fun, not fun at all. I have the most sensitive skin of anyone I've ever come across.
If I had to guess, which apparently I am, you have more than one thing going on. #1, you ate something you are allergic to, what it is, I can't tell. The swelling could be from an allergic reaction, but it could also be from eating too much salt. Some people can't tolerate much sodium, like me. #2, I think you have a yeast infection, also called Candida, perhaps also systemic shingles. I had them both at the same time. Most of the areas you described with a rash, like inside elbows, under arms, etc. are moist areas where yeast grows. Guess what feeds a yeast infection...vinegar, bakers yeast (yeast used to make bread), a mold exposure, nuts (molds grow readily on nuts), cheese and fruit, too many carbs. Taking antibiotics can also cause a yeast infection and rash. Because your skin was already sensitized from the previous poison ivy exposure, your reactions are coming out on your skin. Most doctors only recognize the common female yeast infection, and don't know that it can be systemic, like I had.
Here's what I would do if I had your symptoms: stop all vinegar, cheese, bread. I'd even stop using Splenda, I've heard of people getting a rash from Splenda. Go on 'the cave man' diet, which is lean meat and fresh low glycemic veggies for a few days, no artificial sweeteners or artificial colors or additives. Drink only water, plenty of water, filtered or mineral water if possible. Wear only soft cotton clothing, and try to find some all cotton sheets...the rash on your hips could be from either the seams in your pants(sewn with polyester thread) or the polyester in sheets. The seams on the inner thigh area of pants could easily irritate already sensitive skin, especially those of us with 'thunder thighs' so wear a dress or skirt, cotton if possible. Wear a slip inside out so the seams are not touching your skin, hopefully a non-polyester slip without lace. A rash around the ankles can be caused by wearing socks that are rough or too tight around that area. If you can tolerate it, a medicated powder like gold bond might help in the moist areas. Have you changed your laundry detergent lately? Make sure you put your laundry thu an extra rinse if you can. Don't put any scented products on, and especially don't wear any alcohol based perfume, cologne, etc.
There are prescription medications to help fight a yeast infection, I would suggest you speak to your gyne (I am presuming you are female), they know more about yeast infections than most Internists. (Sorry, I'm not sure what CRNP means.)
Most of all, I would suggest that you stay home until you get this under control! I usually take benedryl if I start getting a rash, and 99% of the time, that works for me, altho it can make you sleepy. You need to relax, the more upset you get, the higher your histamine level can go, the worse the rash gets. There is a product called colloidal oatmeal at the drug store that you add to a bath, that can help calm down and get rid of a rash.
I hope all this helps, at one time I actually started writing a book on this subject for the Gulf War Vets who were breaking out in rashes, but my story is so depressing, I had to stop...
In answer to your legume question: legumes are beans. Peanuts are also legumes.
As for food allergies...yes, you could be allergic to legumes, or seeds, or anything you eat. I'm allergic to some beans, but not all of them. I can eat cooked dried lima beans, but not lentils. You have to be your own detective to find out what you are allergic to...it might not be the last thing you ate before getting the rash. Some people are delayed reactors. Try keeping a food journal and keep track of symptoms, too. Hopefully, you will see a pattern of eating a certain food, and getting the same reaction each time.
I hope this helps you, feel free to PM me if you have any more questions so we don't bore the rest of our loyal fans with our problems (ahahaha).
Check out my bean thread, "Burdle's
'You guys interested in bean recipes?', edited" in the Recipe and Food section of this Forum.