Welcome to BYC!
I agree with the poster who said they
look like pekcing wounds, they probably had a disagreement and worked it out, mating season is upon us. Wounds on the comb often turn white on their way to healing like the lighter skin of a scar.
Chickens usually only deal with stick tight fleas on their comb/wattles.. and are not infested with standard cat/dog fleas in their feathers.. according to my understanding. Mites or lice are more likely to be under the vent or abdomen.
Dry skin.. that's it.
Many vaccines are available for poultry in the US including Marek's, coccidiosis, infectious brochictis, and fowl pox.. maybe more.
My suggestion.. let it be.. it looks benign and they should heal rapidly.