This horse, a 7-year-old gelding, is showing some kind of skin reaction around one eye. The lids are dark, but surrounding them is an area of pale, hairless skin. There are no evident sores, scabs, swellings, or fluid of any kind, it's just a pale, hairless area, and it's only on the one eye. The owner says that the veterinarian told him that it's a fly allergy. Is this likely the cause? If so, how can I clear it up, aside from fly prevention measures? Is there an ointment available that can help medicate or protect this obviously sensitive area? Is it even possible to clear this up, or is this likely to be a more or less permanent blemish?
I've included a picture which shows the pale area - sorry it's not any clearer.
Thanks very much in advance for any advice!