Dusky comb with white patches and white debris on head

[EenaLodgePT]

Hi. Clara is about 18 months old. 3 days ago, I noticed that her comb was purple fairly suddenly. She doesn't have the use of one leg, so she's always fairly quiet but likes to get in the mix with the flock of about 35 chickens and 5 Guinea fowl. I separated her in my "infirmary," washed her, gave her some supplements. She has no symptoms--no respiratory signs, no diarrhea. I can't find mites or lice on her or the others although many are moulting right now and I'm new to all this, so I could miss something. It seems like fungus from what I glean in other threads. Any thoughts? Because I'm in rural Portugal, there are really no veterinary services for chickens (unless you're a commercial farmer), and the usual treatments in other places for mites and such are not available here except things that would require egg withdrawal. I co-manage this flock with my neighbour, a villager who has been open to trying new things but is very traditional. I started fermenting the layer feed (plus some scratch feed) over a month ago, and they all seem to love this. At first I thought the white debris might just be adherent bits of mash. It's been a wet mess here weather wise for the last 2 weeks. I've included some pictures of others in the flock. Thanks for your advice.

 

[dawg53]

It could possibly be Favus, a fungal infection similar to Ringworm. Treatment is Miconazole or Lotrimin cream applied to effected areas twice a day until cleared/healed.
Wear disposable gloves when applying the cream.

 

[MysteryChicken]

I see white Urates, it's even in the crest of the last one pictured.

 

[EenaLodgePT]

It could possibly be Favus, a fungal infection similar to Ringworm. Treatment is Miconazole or Lotrimin cream applied to effected areas twice a day until cleared/healed.
Wear disposable gloves when applying the cream.

I’ll try that—thank you.