Mali uromastryx emergency?

i posted last night about the care so thanks to all those who replied it helped me alot! but today i went and purchased a male to go with my female and i have him in a separate tank like i usually do as a precaution to make sure he doesnt have anything to spreda to my healthy female. he is in a 50 gal breeder tank with reptile line and two half logs and a 100 watt uva/b basking bulb positioned about 15 inches above a smooth rock. well i just noticed he has a knot on the left part of his shoulder? and its bleeding a lil i think im not sure cuz its a sticky substance but it is or has a red hue to it. so what could have caused this? im worried sick about the poor guy and idk what to do i applied a lil neos to it but im still scared i mite loose him and i called my exotic reptile vet but the earliest he can see me is wednessday. im really afraid i might loose him. could it be the light? idk? please help