Here are several more references to the long sneezing fits this country singer suffers from when her allergies act up. From a comment on a YouTube thread:
"I once met Martina McBride at Fan Fair in Nashville back in June of 1999 and she had two sneezing fits while I was in line and taking a picture: One set of 14 sneezes in a row in less than 14 seconds and another of 18 sneezes in as many seconds. I was ready to take a picture with her, til she turned her head and said; "oh. wait.. wait." with a presneeze face."
There was also this mention of allergies during one of her shows.