Stories of vampires — fictional blood-sucking beings that appear in folklore — may have their origins in real people who suffered from a rare genetic blood disorder that caused the skin to blister under sunlight, a study has said.
Porphyrias, a group of eight known blood disorders, affect the body’s molecular machinery for making haeme, which is a component of the oxygen-transporting protein, haemoglobin.
Erythropoietic protoporphyria (EPP), the most common kind of porphyria to occur in childhood, causes people’s skin to become very sensitive to light. Prolonged exposure to sunshine can cause painful, disfiguring blisters.
“People with EPP are chronically anaemic, which makes them feel very tired and look very pale with increased photosensitivity because they can’t come out in the daylight,” said Barry Paw, from Boston Children’s Cancer and Blood Disorders Center.
Staying indoors during the day and receiving blood transfusions containing sufficient haeme levels can help alleviate some of the disorder’s symptoms.
In ancient times, drinking animal blood and emerging only at night may have achieved a similar effect — adding further fuel to the legend of vampires, researchers said. The study was published in the journal Proceedings of the National Academy of Sciences.