HI Everyone
Thanks so much for your input. I am now almost 100% convinced the tics I have seen are allergy related. Matthew is now on a strict gluten free, dairy free and processed food free diet and seems to be much better. No tics and major behaviour improvement too. The allgry elimination clinic has really helped too.

Will see how we go as he is really missing the dairy - I will reintroduce in a few weeks and see what happens.

best regards
Sarah