Hi, Noted the history about your 4 year old son having inherited rhinitis from Mother and Father, tried oral and nasal decongestants, corticosteroids but the problem persists, wants to know whether you can give him injection Diprofos as you are using for the last 5 years. First of all, remember to have a proepr diagnosis by an Examination by an ENT and Pediatrician. No self-medication at home. No such injections as you have mentioned unless advised by your Doctors as your child is just 4 years old. The commonest cause is surely an allergy hence for the baby and you and your wife the following things will help a lot. Try to identify the factors that is instigating or enhancing the allergy like dust, pollen, anything in foods and beverages. molds, mildew in house or around. Prevention is better than cure hence the best way is to avoid all such causes. Get Vitamin a And D estimates. If deficiency is corrected many a patients get the best results. Also go for the medicines under the guidance of an ENT Surgeon and a Pediatrician. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. T. Chandrakant, ENT & General Surgeon