I had never heard of it, either. But my husband named off the childhood ... er... sicknesses (LOL) and there ARE/WERE five of them.
My son told me basically the same thing that you said, Cheri, so I guess it's back to square one. I'm gonna read up on the links that have been offered. Probably won't know anymore than I know now but I might feel better!

EEESH! Once a mother, ALWAYS a mother!

I noticed the four sudden responses all at the same time! LOL
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Psalm 119:105 Thy word is a lamp unto my feet, and a light unto my path.