I sneezed six times in a row this morning.
Six times may be simply an histamine reaction to dust or mold.
The first time I had a stroke (well, as far as I know, it was the first time), it manifested as a sneezing fit. I lost count of the number of sneezes at just over two hundred as I was trying to drive home from work (my last job - I was many miles from home when it started). Driving is a bitch when you can no longer see and your mind is also pre-occupied.
I went to the doctor the next day, because all night I had not stopped sneezing. They gave me a shot and it stopped, almost instantly. Then they ran some tests and determined that I had had a mild stroke.
None of the attending physicians had ever seen or heard of a stroke taking this form in a human, but it has been known to kill some animals, simply from sneezing.
I am sure that I lost something of myself, if their diagnosis was correct, but I had no noticeable effects, afterward.
I don't really think you need to worry about six in-a-row sneezes.