My family doc said they are useless for DD's eczema testing as intolerance will not be picked up and allergies can be developed later on.

I really wanted to get DD tested too but the children's hospital always gave me the excuse that they were too busy (long story)

Anyway, the advice i got from DD's dust issue was to get Allergend (which is a dust mite cover for the cot) or to change the cot sheets regulary.

Make sure the room is clean and no mould.

Best of luck