I've a flock of 1 & 2 year-old primarily hybrid free-range layers. One suddenly has at least 50% of her comb and 25% of her wattles covered in irregular gray patches. Looks very geographic. Not from insect bites or any sort of scab. Hen acting fine. No swelling. No recent changes other than intolerable heat, resolved this week. Ideas? Have pics if someone could tech support me through attaching with iPhone.