What Causes Spots Along Waistline While Using Kigtropin HGH?

I had one small spot that I concluded to be simply irritation from my clothing along my waistline. The single spot quickly turned grew and now multiple spots have appeared as well as smaller red bumps in a sort of hive collection. I m using Kigtropin HGH and have been for approximately 3-4 weeks. This is the only serious change in diet or supplementation etc that I can think of possibly causing the rash. Is this a common side affect of Kigtropin or any HGH product use or something entirely different?