Does anyone else out there have a wee one with a niggly cough that has been coming and going for months (DS had a niggly cough that's worse at night since August). Doctors have said chest and lungs are clear and don't know why he's coughing. Just finished and anti-biotic which helped for a couple of weeks but cough is back again (nose a little runny too) and we wondered if this was down to his teeth - anyone else experienced this?