I only get this on my hands and some weeks my hand looks so bad I am embarrassed! The worst part is, now I know if I scratch them hard enough the "blisters" will pop and stop the itching for a bit.
It is very frustrating that no Doctor can diagnose this!
So glad that I've found other with this condition. I manage to not scratch most of the time now, but every now and then the itching drives me mad and I scratch until my skin is raw. I've had this condition since I was 18, I'm now 59. It used to occur on the tops of my ring and middle fingers on both hands. It has migrated now to the sides of my ring and little fingers, also to the top of my big toes. (that's just weird to me, that it is only on the top of my big toe).
Two things I'd like to mention from my research and feedback on some other postings:
I believe the condition to be Dyshidrotic Eczema (http://emedicine.medscape.com/article/1122527-overview). The link has a very good section on treatment; of which I find 1% Hydrocortisone cream to be very effective in managing symptoms. Also I've soaked my hands in hot water when the itching got to be too much and it provided some temporary releif.
The second thing is I've seen some very extreme things mentioned in these postings (sticking hands in bleach for one) and although the pain and itching can seem overwhelming; I'd like to caution you to calm down and relax before trying something drastic.
tl;dr 1% Hydrocortisone cream or ointment or soaking hands in hot water.
I've noticed all of those correlations in myself---sugar, stress, cold/lack of sun exposure--and they do tend to from very quickly. Mine sometimes itch before they dot and blister.