S.M.
My daughter has extremely sensitive skin, I've had to switch our detergent, body lotion, and soap - basically everything that touches her! I started covering her in Aquaphor after every bath and it's helped a lot. We also have to tell anyone who visits not to wear perfume or her skin will break out wherever she touches them.
If you are concerned don't be afraid to push the issue with your doctor. You are the mom and you know your baby better than anyone - trust your gut!