Dry pox is usually not serious, unless there are secondary infections. Wet pox is very serious. Make sure they continue to eat and drink normally. Your pictures look like dry pox.
Have a look at these articles where there are many pictures, and information about pox:
https://www.backyardchickens.com/a/avian-pox-how-to-treat-your-chickens-for-avian-pox
http://www.thepoultrysite.com/publications/6/diseases-of-poultry/195/fowl-pox/...
When I get on my computer I will post some links and pictures of fowl pox. It is a virus spread by mosquitoes that lasts 2-3 weeks. There is usually no treatment. Some dab a little iodine on the scabs, but don't disturb them or you can spread the pox. Any scabs near the eyes, and it would be...