User blog comment:B214/Volume 23 discussion blog/@comment-124.168.134.41-20170402000720/@comment-3965848-20170402005550

The thing is the whole being "allergic" to sun light is a real life rare condition called Erythropoietic Protoporphyria or EPP that some humans have, a girl on the news is said to have it and Vlad the impaler (the inspiration for Dracular and the Vampire mythos) is also noted to have had it.

While painful it doesn't kill immediately, in fact the chance of death is rare but still a possibility.