Thank you for your question. I think that you are in a very dangerous position in the sense that the treatment plans you keep being prescribed are in fact probably contributing to the prolonging of the imbalance that underlies the disease process in your son. If you continue with this routine of pharmaceuticals every three months by the time your son turns 5 his immune system will probably be in quite a depressed state.
My recomendations to you would be to firstly find a practitioner who will try to heal the immune system and not keep treating the symptomatic infections. You are more than welcome to contact me at www.healthnation.co.za if you would like to set up an individual appointment. The reason I suggest finding an understanding practitioner is because there are a multitude of treatment protocols that boost immune functioning, too many to discuss in this reply.
Secondly I would begin with his food - cut out all forms of immune-taxing foods like sugar, gluten, dairy, preservatives and artificial flavourants and sweeteners. Secondly change your probiotic to something more targted at healing and not just maintaining health. Thirdly, under supervision of your health care practitioner, I would begin trying cycles of healing botanical herbals that have been shown to boost immune functioning. Additionally consider a strong high-grade omega 3 supplement at double doses.
I would also ask you practioner to exclude any functional anatomical abnormalities that could be contributing to the upper respiratory tract being more susceptible to multiple infections.
Many thanks and warm regards