Two of my horses have the same problem. My Vet suggested putting them on an antihistamine - I use HistAll - I get it from Valley Vet. I can say it has worked well this past spring and I am still using it because of bites. My Vet also told me to get some Vitamin E oil and use it on the face. She said it could help with hair re-growth. I use a horse shampoo that has Tea Tree Oil in it - that seems to help with itching. I use a medicated shampoo for the tails. Good luck - hope this helps.