Seven year old suffering from Atopic Dermatitis

Hi,
My son (7 years old) has been having atopic dermatitis for last 5 years so. For last 3.5 years, it is getting worse every year. In my wife's family, there are breathing disorders. In my family, we have stomach disorders.My wife has also allergic bronchititis but it is under great control after she took homeopathy treatment. For my son, we have tried allopathy, Ayurveda and Homeopathy. Nothing has helped him till now. His condition has been going from bad to worse and nobody is able to control it till now. Bad areas for him are legs (knees, upper legs, crotch area, genital area), hands (joints area), front of neck and little bit on face too. He has undergone hopmeopathic treatment from 3 doctors for last 3 years. Nothing has helped till now.
Earlier he will be itching many times in night. He will wake up many times in night every 2-3 hours. He gets very sound sleep only in early morning like after 6:00 am. Also if he sleeps in day time or in evening for 1/2 hour, he always starts itching. On weekends, he sleeps well till late hours like 10:00 am or 11:00 am. By nature, he get irritated easily and cries for very trivial things. He is now psychologically affected as he often says that why only he has this itching and not other kids. He has been now put on following medicines:
Now we have come to Doctor number 4. After some 2 weeks of trial, now following medication seems to have helped him a little bit as itching has come down. He has been able to sleep slightly better now.
Apis Mel 30 x
Ars Alb 30 x
Rhust tox 30 x
urtica urens 30 x
in 10 % v/v

It appears to me that these medicines are highly strong. Would like to know whether these are suitable.
Any suggestions on improving my son's condition will be highly appreciated.