I have been treating and teaching the Gua Sha technique for several years, never met a case like it metioned here: skin infection, or cellulitis. I don't know why Dr. Lin(?) draw the conclution that Gua Sha is not safe. Accupuncure and the cupping is more for the professional, not the public, but the Gua Sha is very safe for the public,it's easy to learn, to perform no matter if you know the mariden or not.