
Hi Sue
From the description and your lad's reaction it sounds similar to a hot spot which one of mine had many years ago that turned into wet excema. It was clearly uncomfortable and treated with a special cream which whas used to quite firmly wipe the area removing any flaked/scabbed areas repeatedly until it dried out (cream wasn't to be obviously left on the affected skin). It did require that a fairly large patch of coat was cut away which took almost a year to eventually disappear but that was of no consequence as the main thing was the problem cleared up (from memory) in a couple of weeks.
Hopefully it's something even less bothersome for your lad but if it turns out to be this it's thankfully not serious however exacerbated by too much grooming so best keep that to a minimum around the area until properly examined and diagnosed :)
regards, Teri