Strange Diseases: The "Vampire Ailment"- Xeroderma Pigmentosum

Xeroderma Pigmentosum (or simply XP) is a medical condition that makes people ULTRA photosensitive, among other things.

It is sometimes called the Vampire Ailment, because some of those afflicted can only safely go out at night (as I understand it.)

I first learned of the illness by watching a film some years ago, which if I recall correctly is called "Children of the Night" or "Children of the Dark". It was a Lifetime movie.

I'd link it here if I could find it on YouTube or Dailymotion, feel free to look it up yourself.