[cypher]

It's hard to know what might cause it unless there's something in the cage he could be rubbing against, it doesn't sound like it's a result of fighting.
The best thing for dry skin is some extra flax seeds (linseed) in the diet, a pinch daily is fine & evening primrose oil, a drop a day on food.
If they are fighting it could escalate at any time & one could get very badly hurt or worse so you should really think of separating them & if Bandit is the submissive ham the stress of living with the other won't be doing his health any good generally.