Itchy but nothing to show before

[paranoidmother]

My DD (5.5) is scratching a lot of the time. Sometimes she isn't but it seems as though as soon as she has nothing else to do she scratches. She doesn't bite her nails so they are long (even with lots of trimming) and leaves angry red marks across her body from scratching so much. Sometimes, not too often, she'll draw blood but only very very tiny spots.

She complains that something is biting her at bed time and we're changed the bed completely and bed clothes. I don't use anything in the wash apart from Eco Balls. Air dried most of the time unless pouring with rain. It's not just at bedtime but during the day as well.

There are no spots, no marks anywhere on her before hand. No other symptoms that i'd associate with allergy. Is this possibly an allergy or is it just bored and now a habit do you think?

Sorry for the rambling but I wasn't sure what to do about it.

TIA

I am sure you have thought of this but is it eczema? My daughter has bad eczema but a lot of the time it doesn't show iykwim, she is mixed race so it is not as easy to see as on pale skin but she still scratches like mad even when there doesnt seem to be anything there. Is it localised or general itching?

It could also be an allergy. My LO has lots of food alergies and some tend to make her itch more. Allergies manifest in so many different ways so it could be.
BTW My GP was useless when I first took my daughter and several GP's dismissed her as only having borderline eczema and just prescribed aqeous cream (which did nothing) It took a few months of her scratching herself to pieces and it getting infected for it actually to be diagnosed by a dermotologist at the hospital.
Can you think of anything else :wheezing,runny nose....iritability on/after eating,stomach aches?

there doesn't seem to be any other symptoms apart from mostly it seems to be at bedtime. Once she takes her clothes off and then when in bed. During the day when she's fed up or bored.
Will see if I can find anything that sets it off more than others in case it is an allergy or eczema. If I've tried the allergy way by the time I get to the dr's then I can tell them a bit more.

Thank you for your help