It sounds like a combination of things to me really. If you already noticed it being worse when you eat wheat and sugar, then you probably do have the sensitivity to wheat but that can be commonly combined with candida and also parasites. I have had this before, and I also have an allergy to wheat. I don't have a problem eating live grains like Ezekial Breads, and I have no sensitivities to rice, so I stick with rice pasta, wheat free waffles, etc.
The itching and rawness you describe really do sound like candidas, and when you say that it improved with your diet, that just makes sense.
It would be a great idea I think to do a complete parasite cleanse before doing a liver flush, or any other type of cleanse, because from what I've read, so many other imbalances including these allergies, candida, etc. can happen as a result of parasites, and before you cleanse the other organs it is apparently a good idea to get rid of any parasites before trying to flush out the liver, etc.
Have you also ever tried the allergen free diet where you eliminate all foods that are the most common allergens and then try again (on isolated days) those foods again to see how you feel?
I have been tested before as being sensitive to corn, soy, wheat, and dairy -- quite a list, but frankly, after eliminating wheat for the most part, I don't feel as sensitive to the others. I don't really miss the wheat either, and everytime I eat it I immediately feel tired and not so great the next day, irritable etc. So for me, there is no question that my body doesn't like for me to eat wheat.
Bottom line, if your dietary changes improve the situation you probably already have your answer. Because it would seem, if it was a bad bacterial infection or something that what you eat would not improve it, and you'd need to see a doctor. I don't know if you are opposed to just a basic anti-itch creme, but in a desparate uncomfortable situation, that will just temporarily eliminate the discomfort. I don't know much about the complete anti-fungal diets, but if you have bad candidas, I guess there is that whole list of foods to avoid since they promote it. I always eat tons of garlic which I know helps, and take acidophilus.
I think everyone could use a good parasite cleanse anyway, and that's a great place to start in my opinion to get everything in balance.
I'm doing the Dr. Clark Purity products one now, and have been on that for about a month. Last week was my turning point and I feel better than I've felt in a long time. My skin looks so much better (looked horrible last week, something was definitely detoxing) , and I feel really just have so much more energy.
I hope you figure it out!