What Causes Sporadic Gagging Cough In A Child?

Daughter has a sporadic cough, usually about 5 times a day. Very rough gagging cough that usually ends with a sneeze and then she recomposes herself and seems fine. She is 11. Doctor has tried acid reflux medicine and other cough remedies (she takes childrens Claritin normally) and we are now down to seeing a pulmonary specialist as the only option.