Had a nurse attempt to place an Iv in the patients right anticubital and missed. Went to the left and the patient started having welts, redness and inflammation on the opposite arm. Patient took Benadryl and the redness went away but the swelling continued. The md was baffled because if it was an infusion reaction, why the opposite arm? Thought maybe the vein was punctured. Any insight would be helpful to the mystery!