By Neil Osterweil
Reviewed By Michael Smith, MD
WebMD Feature

"From ghoulies and ghosties and long leggety beasties, and things that go bump in the night, Good Lord deliver us!," begs an old Scottish prayer. Fear can have a powerful grip on the unenlightened mind, but there is tantalizing evidence to suggest that legends of ghoulies and ghosties may be based in boring old reality.

Consider, for example, this description of the title character of Bram Stoker's Dracula:

"His eyebrows were very massive, almost meeting over the nose, and with bushy hair that seemed to curl in its own profusion. The mouth ... was fixed and rather cruel-looking, with peculiarly sharp white teeth; these protruded over the lips, whose remarkable ruddiness showed astonishing vitality in a man of his years ... The general effect was one of extraordinary pallor."

The bloodthirsty Count's physical features could have been caused, say some researchers, by a rare but very real disease. It's called porphyria cutanea tarda (PCT). PCT is the most common form of a genetic disease that results in abnormal pigments. And what part of your body needs these pigments? Your blood, of course -- specifically hemoglobin, the oxygen-carrying part of red blood cells.

People with PCT have skin that discolors and develops rashes and blisters when exposed to light. Those with more severe forms of the disease may have excessive hair growth on their face and hands (Dracula had hairs in the centers of his palms), gum degeneration (causing the teeth to appear large and protruding), and brain disorders. Some chemicals, including those found in garlic (a bane to vampires) can make their symptoms worse. Sometimes a person with PCT doesn't have enough red cells -- and needs repeated transfusions of blood.

"These symptoms, disease management strategies, and treatments are clearly reminiscent of characteristics typically associated with vampires and werewolves, and it is widely assumed that folkloric reports of such beasts may, in fact, be based on the suffering of unfortunate individuals afflicted with porphyria," writes plant geneticist Crispin B. Taylor, in the journal Plant Cell.