The enzyme (hematin) necessary to alleviate symptoms is not absorbed intact on oral ingestion, and drinking blood would have no beneficial effect on the sufferer. Finally, and most important, the fact that vampire reports were literally rampant in the 18th century, and that congenital erythropoietic porphyria is an extremely rare manifestation of a rare disease, makes it an unlikely explanation of the folkloric vampire. Notable cases
King George III. The mental illness exhibited by George III in the regency crisis of 1788 has inspired several attempts at retrospective diagnosis. The first, written in 1855, thirty-five years after his death, concluded that he had acute mania. M. Guttmacher, in 1941, suggested manic-depressive psychosis as a more likely diagnosis. The first suggestion that a physical illness was the cause of King Georges mental derangement came in 1966, in a paper called "The Insanity of King George III: A Classic Case of Porphyria", with a follow-up in 1968, "Porphyria in the Royal Houses of Stuart, Hanover and Prussia". The papers, by a mother/son psychiatrist team, were written as though the case for porphyria had been proven, but the response demonstrated that many experts, including those more intimately familiar with the manifestations of porphyria, were unconvinced. Many psychiatrists disagreed with the diagnosis, suggesting bipolar disorder as far more probable. The theory is treated in Purple Secret, which documents the ultimately unsuccessful search for genetic evidence of porphyria in the remains of royals suspected to have had it.
The addition of hematin or heme arginate has been used during status epilepticus.Depression often accompanies the disease and is best dealt with by treating the offending symptoms and if needed the judicious use of antidepressants. Some psychotropic drugs are porphyrinogenic, limiting the therapeutic scope. Other psychiatric symptoms such as anxiety, restlessness, insomnia, depression, mania, hallucinations, delusions, confusion, catatonia, and psychosis may occur. Underlying liver disease
Some liver diseases may cause porphyria even in the absence of genetic predisposition. These include hemochromatosis and hepatitis C. Treatment of iron overload may be required.Patients with the acute porphyrias (AIP, HCP, VP) are at increased risk over their life for hepatocellular carcinoma (primary liver cancer) and may require monitoring. Other typical risk factors for liver cancer need not be present. Hormone treatment
Hormonal fluctuations that contribute to cyclical attacks in women have been treated with oral contraceptives and luteinizing hormones to shut down menstrual cycles. However, oral contraceptives have also triggered photosensitivity and withdrawal of oral contraceptives has triggered attacks. Androgens and fertility hormones have also triggered attacks. In 2019, givosiran was approved in the United States for the treatment of acute hepatic porphyria. Erythropoietic porphyria
These are associated with accumulation of porphyrins in erythrocytes and are rare. The pain, burning, swelling, and itching that occur in erythropoietic porphyrias generally require avoidance of bright sunlight. Most kinds of sunscreen are not effective, but SPF-rated long-sleeve shirts, hats, bandanas, and gloves can help. Chloroquine may be used to increase porphyrin secretion in some EPs.