White patch on arm

[Geralt]

Hi,

Recently switched to coco coir, humidity is kept around the 50% mark for this greek moroccan species but I've just took him out today and noticed this strange white mark on his arm. I'm not sure what it is or if it's something to be concerned about.

 

[zolasmum]

Welcome from Devon. Have you tried washing his arm thoroughly - could it be some urates stuck there, or something similar ?
Angie