Omnicef and arms and legs

Recently, my 12 month old son was prescribed Omnicef for what the Doctor thought was strep throat. Before the medication he had a steady temp of 102 and was very un-energetic. After five does of 1 TSP my son broke out in a horrible rash all over his face, torso/truck, and upper part of his arms and legs. He also got a diaper rash and diarrhea. He also was very bad tempered and moody. This was such a change from his past behavior, even when he was sick. The doctor thinks this is an allergic reaction to the mediation and put him on another antibiotic. I am very concerned about this medication and it's side effects. It seems that eveyone is experiencing some very serious things.

My 6 year old son had a photosensitive reaction to Omnicef on his 10th and final day. That night it appeared as if he had gotten sunburned but he was also crying that his feet and palms were itchy. The next morning we could see welts on his trunk that moved to his arms and legs. The rash moved around and gradually improved over the next week. But now, three weeks later the welts/hives are back again and seem to be getting worse. They went from his trunk, to his arms and legs, and are now on his face, scalp, and ears, and his feet. Omnicef is not suppose to be photoreactive from what I have read, but this is the only thing that could have caused my son's reaction. My advice - do not take any antibiotic unless the condition is life threatening or will end in a loss of function.