What is this? Help

[BackyardBreakfast]

this is my "10 week old" barred rock chick (my guess is roo) it seems to have a wetness on the underside, maybe from laying in poo or is it something serious? What is your guess this is?

 

[rebrascora]

Since it seems to have a bare swollen patch of red skin I wonder if it has had a cist or abscess burst. Can you give it a soak in warm Epsom Salts solution and clean it up and see if there is any obvious wound. It may be it has just been paddling in the water and then the dirt has stuck to it's wet feathers but a thorough wash and exam would be pertinent.