Ihsan, make sure you supplement your son's diet with essential fatty acids like evening primrose oil or flaxseed oil, preferably cold pressed. Also give him a good probiotic.
As to the link between steroids and eczema, I have learnt that steroids may cause eczema because it works by weakening the immune system. Prolonged use of steroids will weaken the immune system to the extent that the body is not able to fight off common pathogens including a fungi commonly found in the intestines called candida. Over time the candida will proliferate and its roots will "bury" into the intestinal wall causing perforations. As a result the intestines become more permeable and will allow undigested food particles and toxins from the gut to pass into the blood stream. The result is eczema. Prolonged use of antibiotics may cause the same result as it will kill off the beneficial bacteria in the intestines. These good bacteria naturally found in the gut actually keeps the candida in check and killing them off will cause the candida to multiply as well. Go ahead and Google this. There are tons of info on this.
This is why I have stated previously that steroids are bad and will actually cause the eczema to worsen. If fact this was what happened to me. I was on steroids for 18 years (doctors did not warn me about the side effects) and my health and eczema became progressively worse.
Contaxable, you said that you managed to overcome your eczema. Care to share with us how you did it? May also help if you could find out from your staff and let everyone know which TCM doctor she brought her son to.
Ihsan, now that your son is back on steroids, monitor him closely. If he develops stomach ailments, it is time to re-think whether steroids will actually help in the long run.