Possible mites on a foal

[SharonBirt]

My 6 week old foal who was 3 weeks prem and had a typical prem foal coat, is scratching off the hair on her head, although I haven't seen her do this incessantly it is enough to remove areas down to the skin.
I did have a mare who use to rub off her face hair off through mites and use to treat successfully with frontline spray.
I'm just concerned that she (unrelated) is also mite sensitive and as she has such a fine coat at a loss to know what to put on that's not going to irritate more.
I have yesterday washed her face and neck with Dermoline shampoo, and am going to start putting aloe jelly on the skin tonight.
I've just had a look on the bag of stud and young stock mix and noticed that it contains flaked barley, is this something which is known to cause irritation?
Any other suggestions welcome please.~

 

[AmyMay]

What does your vet recommend? Are the out or in during the heat of the day? Is the mare affected as well?

 

[SharonBirt]

What does your vet recommend? Are the out or in during the heat of the day? Is the mare affected as well?

They have the choice, big open barn leading out to paddock, they have been spending more time in during the day as it's so hot. I'm wondering whether the straw is irritating her, and have a mind to burn the lot and revert to a chopped rape straw bed.
The dam is not suffering, although has contact dermatitis on her white fetlock due to possible photosensitivity. She's not itching though. :-(