My nephew has a painful sore on his scrotum, it s been there for weeks. He s been tested for std s and hiv but negative results, he also has broken out on his face terribly and they said it was merca, I think he s using drugs but an not sure. He has taken antibiotics for the issue but, lies about going to the doctor and taking his medicine....I know he used heroin in the past, could this be the cause of the problem?