I have type 2 diabetic, age 66 and when I went to the dentist for my swollen molar tooth, I was prescribed erythromycine and after taking 3rd day I broke into a rash like goose pimples and very itch on my elbow, arm, legs and body. I am also taking meds - metformin, lipitor, altace & supplements like multivits, CO10 and calcium liquids for health. Am I allergy to this erythromycin to cause this rash or are they conteracting with my other meds.