I also raised a bunch of ski racers. In fact, I used to get my cough going every November when I'd hike up a mountain early morning about 10,000 ft, boot packing, to reach the finish line of the opening Noram slalom races at Loveland Pass, COLO , — high altitude, especially since we came from coastal, maritime environment — i..e. zero altitude, all of which would freeze my lungs and trigger my Mac cough. For many years it lasted about 6 months, then it started staying all year, which, accompanied by nodules on CT scans, is what prompted me to get testing that disclosed MAC. Where were your kids racing? Mine ended up racing all over.