Hillstream Loach Sick! Help!

[rockythebetta]

Bought Mari earlier today, and started the acclimation process when I noticed a rather large red sore

 . She has since been moved and released into a quaratine tank.  It's so disappointing when you buy from a place you trust and this happens...
 
What could this be? How do I treat it? 
 

 

[Baccus]

I know Borneo Suckers and Hill Stream loaches are the devils own spawn when it comes to catching the cheekie little devils (I do love the dear little guys but they are still as frustrating as hell to actually catch), so I am wondering if perhaps it got injured during the catching process in the shop? Even the most experienced fish keeper (catcher) can have problems with netting these guys especially how they will wriggle between the edge of the net and the glass to escape capture.
In the pictures it doesnt appear to be an open wound, so I would keep an eye on it, make sure the water stays clean and ensure the loach has no problems eating or moving. Hopefully its just some localised bruising and it will go away with some time to heal.