Just to let you know I've had horrendous itching in fingers and toes - coming from inside, not atopic like contact dermatitis or eczema or anything - for a few years now (in fact one of the first ever symptoms was like a red bump coming from inside on toes then fingers, under my skin, v, painful and sore) and was desperately looking for a cure, and I believe I've found it. My cure seems to be sugar! i.e. avoiding it completely. I also had huge splits on the skin of my fingers which have almost completely healed after just 10 days sugar-free.
It's early days so experimenting if have to cut absolutely all sources of sugar or not (e.g. I've had a small amount of fruit). But in the last 10 days I've had absolutely no itching at all!!!!!! Just a little hotness and swelling in the fingers when I eat which dies down after 2h max. I'm trying to stick to eating a lot of proteins (although I don't digest them well so still have to have carbs), as I find any carbs will set my hands off with swelling, getting really hot, skin getting tight and cracking again. But this is improving every day.
I always suspected sugar was the cause (I've been a sugar overeater for >50 years!) but couldn't understand why exercise would set it off too, and so thought it might be more complicated than just one food item. That was a red herring tho, cos exercise merely releases sugar into blood stream from stores in body, e.g. from liver - more research needed by me - but I’m so excited wanted to too.
Also apparently starvation (I used to go long periods in the day without eating so I could eat more at night) and possibly gall stones - again more research needed - causes the liver to kick out bile salts into blood stream which get into the skin and cause terrible itching.
So avoid all added sugar (even in prepack meals) and cut back on any other sources - e.g. honey, fruit, etc - also dairy acts a bit like sugar in body, so cut milk n' cheese too - just for a while to see if it works for you. (Eggs n' butter are fine though.) Also wine, any alcohol would set me off too - has a sugar effect in body.
I found choc was SO difficult to give up! but it's been 10 days now - yay!!! I could of course have 100% cocoa as a sub to get over cravings but gone cold turkey. SO worth doing and long may it continue! Let me know of your experiences if you can. Do you eat a lot of sugar? If you cut it out, does it work for you too?
PS I also have bad circulation in hands and feet, v. low blood pressure, so don't know if that's relevant too. And I sit at a computer all day...
PSS Having read the thread, I'll have to see if vit B12 works for me too - thanks!