* I would suggest you check to see if it might be acid reflux or heartburn. This causes a dry cough because of the acid irritating the oesophagus.
If the problem turns out to be school, why not consider home educating? – Barbara Stark
* My son suffered similar symptoms. A homoeopathic doctor diagnosed swollen adenoids that were dripping into the back of his throat. He prescribed silica and the symptoms cleared up within a month (although individual consultation is recommended to obtain a personalised treatment). – Maggie Stocks