My 4 year ol ds has had a cough for the last 6 or 7 months i think. Sometimes during the night keeping him awake and some weeks just sounding chesty in the mornings and then pretty much fine the rest of the time. The doctor just tells me to keep him on salbutamol but like tonight he's had some before bed and is now coughing. The doctor he sees at the hospital (for low immune system) didn't think it necessary for him to use a preventer. Does anyone else have any experience of this or advice?