New pair of shanjing. I need advices about a little injury in one.

[Fer xD]

Hello everybody, I just receive a pair of beauty T. shanjing, they are very active and eat 2 worms each, (one of them with a drop of febendazol to treat possible internal parasites, as they came from a recently importation.) They're 13-14 cm juveniles, in good shape, but one of them has a little injury in the head's gland. The set up is made of pit and dry soil, a little humid moss and barks. is a bit small i'd change it this week, but i don't wanna get them stressed, so i need some advices about how to treat the injury. (I think iodine solution 10% diluted in water, but i don't know :S) I think it has only some days, cause it has no fungus or necrosis...

the pictures (it's the set up ok? don't wanna do it so humid, but tell me if i'm wrong!)