I have an ER patient that fell and came in with a fracture of the right ulna and an abrasion of the right forearm. I understand you cannot code the superficial injury with a more severe injury of the same site, but the patient was given a tetanus shot, probably because of the abrasion, and I have a medical necessity for this tetanus shot (90715). The abrasion code would cover the tetanus shot, but because it is a superficial injury of the same site, I cannot code it. What do I do with the tetanus medical necessity? Thank you for your help.