What is wrong with my chicken - blackhead?

[Crazy Chicken Keeper]

I have a lovely black chicken who is a reliable layer, bit cheeky she doesn't like staying in. I caught her today and this is her head (both sides):

What is wrong with her? Not frostbite it is summer here. Anybody know?

 

[NotabitaiI]

Do the others look like this and has your flock had fowl pox yet?

 

[Crazy Chicken Keeper]

Never had fowl pox. The rest of my flock is happy and healthy except for a little scaly leg mite.

 

[Crazy Chicken Keeper]

Anybody online? Anybody know? I am genuinely worried and curious about this