Maggie bleeding - need advice

Dear chicken-ey friends I could use your advice.  Tonight Maggie had blood dripping from her wattles.
I don't think it is a life threatening injury but it is dripping.  I noticed it when locking them up for the night.  Nobody is pecking her so for now I have decided to leave her be and will check on her later in the night.
I noticed that she seems to be itchy around the wattles and she has been scratching herself (her toes are blood stained as a result).  I wonder if the injury is actually self inflicted by scratching (I had a cat do that once).
Any ideas on what I should do?  Both tonight/in the morning in a first aid sense and to figure why she is itching?  Otherwise she has been fine all day scratching in the leaf pile with everyone else.  And nobody else is itchy.
Courtesy of the new camera (thank you 
@BY Bob for the inspiration!) you can see them settled for the night and Maggie scratching her face.
Help!