What Causes Severe Itching In Scrotum Post Hydrocele Hernia Repair Surgery?

My son had a hernia repair and removal of a hydrocele on Wednesday. He was on an antibiotic for 3 days and took a pain med for about 1 1/2 days. Last night he started having severe itching in him scrotum. He has taken 2 doses of Benedryl and is getting no relief. He is currently taking no medications other than the Benedryl. Any suggestions would be appreciated. He is also icing the area.