I'm taking GW as well and noticed a bunch of small red spots scattered over my thighs and stomache, but they don't really itch. It could just simply be from Prolonged or excessive Straining associated with heavy weightlifting. I'm not a Dr. but a it could be petechiae (internal bleeding, or leaked capillaries) and there are many causes for it. Read about it and see if that's the case.
What vitamins are you taking? Malnutrition is another common cause of petechiae. You might have nutritional deficiencies of vitamin C, vitamin K, and B vitamins like B9, folate, and B12....