A.,
I had a very similar experience with my son at the same age, about 3 years ago. They thought he had a bad case of cradle cap but he had a rash on his body and his face swelled up like a cherry. Our Pediatrician determined he had Eczema and referred us to a dermatologist (which I would recommend). We received a Steroid Cream (a stronger form of Hydrocortisone) and it worked right away. I was very nervous about this too for such a little one, especially with the bad press the creams were getting at the time. They didn't offer us an oral form, but I hope that works for you. After the initial use of the cream, I used some hydrocortisone very sparingly when a rash came back. I used Aquaphor Ointment, made by Eucerin, every day on his face and body and it works well after baths. Also, a very strange thing, but Neutrogena T-Gel Shampoo helped his head (but once again, I used very sparingly, since it seemed strong for a baby). I tried everything else (every mild, natural cream/shampoo on the market) and this was all that worked for my son. The good news is that regular rashes from Eczema should normally stop by age 1. However, we still put Aquaphor Ointment on him, in the Winter especially. In the summer, we make sure his suntan lotion is one for sensitive skin. I also agree with the responses to use Dreft Detergent and Aveeno Oatmeal Bath Wash. Good luck and just do the research and ask your Drs. lots of questions to keep your little one safe.