Swollen Wattle

[mbshan08]

When I let my girls out yesterday morning I noticed one of them had a swollen wattle that looked to have some dried blood on it. Will this heal on its own or is there something I need to do?

 

[mbshan08]

I noticed where the blood is it looks like a small slice or cut. So I don't no if she cut it on something or if one of the other hens got her.