Anti-allergenic bedding

Unless you have already tried this I would start by buying 'normal' mattress and pillow protectors made of polyester and seeing if this makes a difference. Wash them at 60 degrees to kill the dust mites every time you change the sheets.

I have found the mattress protectors from Primark to be very cheap and generously sized!

We were wondering about buying the full anti-allergy ones but have had such good results from the 'basic' version that we haven't bothered. DH suffers from both asthma and eczema, so I prefer those with a quilted cotton surface, and avoid 'waterproofed' or plasticised ones as he gets too hot.

We haven't found an inner duvet cover of this sort, but they have sometimes been provided on beds in hotels etc - and DH always gets too hot so even if I found one I'd be unlikely to use it.

Edit: for duvets and pillows, know what you're trying to avoid! Again, DH is allergic to feathers, so we've always used polyester filled duvets. But I see Lidl are offering a silk and wool duvet from next Monday, double for £15.99, single for £11.99, and ours is getting distinctly worn, so I may have a look at them. I like solid foam pillows and find they last better than those filled with polyester wadding. Don't know where you'd get that kind of thing cheap, however.