Though I'm not a professional at all. I have seen these on my birds and I find they get these on occasion. When the hens end up with them it tends to be from a rooster grabbing her by the comb to reign her in. When my roosters get it, it's either the result of a fight, or a hen turning the tables when he's trying to grab her.
Since it's the winter here (-30C today!), the birds are locked up tight and though overcrowding isn't an issue, when they're used to being able to wander as far away as they want, they tend to get in more squabbles over the winter while 'cooped up'.
I read your post on another forum, and I don't believe it's frostbite at all. My birds, some of which have very tall combs, seem to have little problems until it hits -25C or so. I have a single heat lamp near the waterer so they have the option to warm their heads, however it's not down very low and I do that for several reasons. The main reason is I acquired 2 Dark Cornish and their feathering isn't very tight at all. I read they're more susceptible to cold, so I installed that for them. Secondly, I'm not interested in having them dependent on a heat source in case of any extended power outage in the worse conditions. My coop is an old restored one and it has its issues, however it remains dry and without drafts. I use deep litter as I have a dirt floor and I've found it remains very nice in there despite having one spot that gathers a little snow on a rafter (which the birds will fight to get at, they love eating snow).
In my limited experience (1.5 winters with birds), frost bite looks different, and is more of a blue colouration, much like your fingers turn when frostbite sets in. I'm 99% that this is simply due to rough foreplay or hen pecking issues. Castor oil was recommended on the other forum, but I've also recently found a cureall for both frostbite and scaly leg and that's the old PetroCarb most of our grandparents used to keep around in the red tin. It's an oil based product (so it suffocates leg mites) that's meant for healing cuts, scrapes and rashes. If it's on this property and has at least one leg, it's been treated with Petrocarb at some point. Send me a note if you want to go where to get some.
Here's an excellent article on Avian Pox, and yours looks nothing like this! All the best.
Edited by Sweetened - 11/23/12 at 7:11pm