D.M.
My son has asthma and now he has developed eczema. He gets his on his elbows and they are white and itchy and a lot of times they spread to the size of a baseball. According to his doctor eczema and asthma go hand in hand. It is due to irritants, something is aggravating him. Usually it is nothing serious but we use "Aveeno" Eczema Therapy Moisturizing Cream (you can get it at Walgreens, Wal-mart, Target etc..). I would try that first give it a few days if you don't see an improvement or it gets worse at that point I would take him to the doctors.