Hope you come back and check for messages. You have tried lots of products but maybe not Florasone Cream. It's over the counter. Whenever I have an itching problem this is what I use.
Are you gluten sensitive or intolerant?
Are you strictly gluten free - diet, body products, anything that might have gluten.
For years I have used only Borax for all washing. No detergents or commerical cleaning compounds. No anti-static in the dryer. No tooth paste - only baking soda and a Water-Pik.
Several years ago I found a report of a group of people who had painful itchy rashes - no parasites, no fungus, no food allergies . Eventually it was determined that these people were all allergic to a dental material in their fillings. Once the fillings were removed and replaced with material they didn't react to their skin problems cleaared up. The report came from a PhD at a paraqsite clinic in the Southwest US, maybe Arizona.
Most dentists I've talked to don't believe this report so you might have to contact the Lab where the investigation was done. Let me know if you want me to spend some time finding the article again.