Lump from Injection

My buddy and I have been hitting 6 ml fort dodge/week (3 per glute every 3 days) for about 3 weeks now and now he is telling me about a bumb on his glute that is bothering him. He says that its about the size of a quarter and itches. For about 3 days after the injection there was a softball size black and blue mark around the site. He says it feels like a bug bite and doesnt hurt, but itches and is pretty hard like a bug bite. Is this an absess or did he hit something on the injection like a vein? What should he do?

make sure that you rub the injection area or it will clump

Oh shit! Looks like I better start rubbing

Heat pack then an ice pack repeat and find a new spot to inject delts . It sounds like he hit a nerve or the depo has crystialized it will pass but is could be cellulosis....then he will need a antibiotic