Hi Doctor, my son is 5 1/2 years old. He has constant blocked nose, stuffy nose, and keeps getting cough and fever on and off. This started since he was 3 1/2 years old. This increases whenever it rains, if the temperature is warm and there is no rain, he seems better. Pedeatrician has advices Metaspray for about 1 1/2 month.. though the stuffiness has decreased, it has not cured fully. Can using this for a long time cause problems ? What is the permanent solution for this. Please advice.