Cough with no other symptoms?

My husband has had a cough for a few weeks now. He only coughs once now and then. He says he has no tickle in the throat. No phlegm either. Could it be a nervous cough? He has had a course of amoxicillin (sp?) but this hasn't helped. We are going on holiday very soon. He took a beechams powder this morning as he said he was burning up in bed. It does feel mild at the moment though. He is stubborn and doesn't want to go back to the GP even though I keep nagging.