We usually perceive vampires as nightmarish, supernatural creatures prone to bloodlust and able to strike terror into the hearts of all who encounter them. Sufferers of a disease called vampire disease, or porphyria to use its real name, may have found in less enlightened times that they were misunderstood or even disbelieved by people associating the condition with the spectres of the night. It seems clear that legends of vampires may well have come from exaggerated accounts of meetings with or glimpses of porphyria victims.
Yet porphyria is a very real ailment, affecting production of heme and porphyrins in the haemoglobin. With symptoms of the disease generally focusing around either the nervous system and manifesting in stomach cramps, vomiting, muscle weakness, mental disturbances and neuropathy (in acute porphyrias); or skin troubles including increased sensitivity to sunlight, skin and gum necrosis, blistering and noticeable hair growth in areas such as the forehead which are typically hairless or very sparsely covered. Exposure to sunlight can also provoke discolouration of the urine to a red or purple hue and receding gums can give the teeth an almost canine-like appearance. These manifestations, along with the fact that sufferers must avoid garlic due to it stimulating the production of heme and causing increased severity of symptoms, have given rise to the association with vampires and the subsequent nickname.
Porphyria is a rare condition, affecting less than 200, 000 people in the US. The most serious form of the disease, congenital erythropoietic porphyria (CEP), is found in less than 1 person per 1,000,000.
Treatments vary, though a high-carbohydrate diet is recommended for all sufferers. Glucose can be given to aid recovery from an attack and the condition can be managed with prescription drugs, though at this time prevention of attacks is not possible and the medicine will simply shorten and reduce the intensity of attacks.