Whiteness all over comb

[thornhill]

Two of my hens' combs are turning white like this:

Based on other threads, people suggest that it's either frostbite, dry skin, or a fungal infection.

We just went through about a week of very cold weather -- mid-teens at night -- and the last few days it has warmed up and rained a lot.

Any ideas what it is and what I should do?

Thanks

 

[Twistedfeather]

To me it looks like dry skin. I rub baby oil on it and it normally gets rid of it. My chickens fet in on their comb and my pigeons get on their feet.