My 5 year old daughter has tolerated Omnicef will each of the 3 times she has taken it. She is allergic to penicillin. This time she was on day 9 of Omnicef when she developed some hives on her hands and trunk. By morning the hives are all over including her face, butt, waist line, feet. They are especially bad around her knees, wrists and elbows. This is causing her a lot of discomfort. She is taking Benadryl and Motrin to manage the pain.