FWIW: Mark and I visited my parents today, and we brought a belated Father's Day gift to my Dad. (I was in MD on Father's Day, so we arranged to get together today instead.)
I mentioned to my Mom that I'd recently discovered I was having an allergic reaction to sunlight (see my post from a few weeks ago). After years of itching without knowing the correct reason why, I was just glad to ID the real cause so I could do something about it, like wear sunblock before going out into sunlight.
SURPRISE. The first words out of Mom's mouth were, "Grandmom used to have the same problem." Say what? My jaw dropped. I don't remember this. On the other hand, Grandmom's health was terrible during the final years of her life, and she only experienced direct sunlight briefly and infrequently (such as to walk, slowly and painfully, from the house to the car). But my Mom remembers Grandmom in younger, healthier years, when she'd come in from hanging clothes in the backyard and promptly have a rash from being in the sun.
Doggone son of a gun. I'm glad I mentioned something today. I'd never have known that I'm not the first, nor the only, person in the family to experience this issue.
Too bad sunblock didn't exist back when my Grandmom would've needed it. That's the first thing I've ever encountered that's done ANYthing to help the problem, and I only started using it recently when I realized that the rash wasn't caused by heat, as I've mistakenly believed for years, but by sunlight.