Large area redness, swelling, itching, hives, starting five days after injection as baseball-diameter area around injection site and traveling down left arm. Some itching relief with topical Cortizone-10 but redness and hives persisted. Some response to Benadryl, but merely temporary; redness/itching continued to spread down the arm for 2 days. Consistent Benadryl use for 6 days showed a response and reaction has abated. Still monitoring for recurrence.