Hi Gwennie,
You have my sympathy - i know excatly how you feel.
I am very itchy right now - mainly on my forearms.
I do not have a visible rash, just a few tiny scabs / lumps where i have scratched and drawn blood. Once the itch-scratch-itch cycle starts it drives me demented. I always try to rub the flat of my hand firmly over the itchy part first to avoid STARTING to scratch ... then at some point i just buckle and start scratching like a hound! It's maddening.
In my case it is definitely linked to sun / light exposure. I always start the day covered by long cotton sleeves with sun block on underneath, but because my job is outdoors and dirty I keep pushing up my sleeves ... then spending hours itching because it is a faf to re-apply sun block when you have soil and grit all over yourself.
I use Aqueous cream like Elizabeth becasue i do have dry skin to boot, so it helps a bit.
If I have none in I extend my hand cream right up to my elbows anyway. I use Body Shop's heavy duty Hemp Hand Cream. I think it is designed for men, but it is a truly thick / great hand cream. Stops my hands from cracking / bleeding in the folds and creases. I wear cotton gloves with rubber palms at the beginning of the day, but the fingers are out after a few hours. If the backs of work gloves are not cotton i itch.
Arms again ... When I know it is linked to the sun and getting ugly I use a tiny amount of hydrocortisone cream in the evenings after a bath / before bed to stop me scratching in my sleep. This is best used after asking your doctor. I use it ocassionally and only a small amount because it can thin your skin with constant use creating other problems. I have also used antihistamine creams.
You can also get Oilatum wash to tip into bath water and bathe in instead of soap, or they do a thicker Oilatum product that is a bit like a cross between vaseline and aqueous cream you can use as a moisturiser or soap - you wet your skin, rub the stuff all over your skin, then rinse it off. Does make your skin feel lovely and soft and it is fine to use it on your face.
If not using soap makes you feel less clean (you are not less clean, but it can feel that way because oilatum has very little fragrance and you miss getting a lather), you could always add a few drop of a soothing essential oil as the tap is running.
Speaking of adding to the bath - ordinary porridge oats placed in an old leg of a pair of tights, knotted, and suspended under the bath tap whilst the hot tap is running can help because there is an enzym in the oats that soothes and promotes skin healing (according to Dr David Bellamy and others). He recommended it for people with itchy psoriasis.
If i was less lazy i really would give it a go. It's on my list!
You can use aqueous cream by the bucket because as Elizabeth said, it is available at cheaper drug stores and is cheap for a great big pot.
Again - my sympathy = hope it doesn't keep you awake at night - I find a hot night in bed sets me off too. I mean hot temperature - not 'HOT'.
Take care and good luck. if you find a one product suits all situations all the time make sure you post about it please.