Let's talk about Halloween from a medical perspective

Author: Dr. Vanessa Santiago Pacheco Medical Pathologist, Laboratorio Clínico Hematológico S.A. Medellín, Colombia.

The scariest night of the year is approaching and at Hematológico we want to enjoy and learn about it.

Halloween has become, after Christmas, one of the most popular holidays in the world. Every place celebrates the night of the witches in a different way; however, many still do not know, not only the fantastic and traditional origin of Halloween, but also the tangible and scientific explanation of some of the typical horror elements of this holiday.

Although we may believe that the roots of this holiday come from the United States and the modern era, in reality its origin dates back to more than 2000 years ago, with the Celtic tribes that inhabited Great Britain, Ireland and northern France. October 31 marked Samhein, or the end of summer, the last day of their calendar and the beginning of winter. The Celts believed that on this night, before the new year, the spirits of the dead returned to earth. During the celebration, they would disguise themselves to hide from the returning evil spirits.

The use of “triqui-triqui”, (trick or treat) also comes from these beliefs; the living feared that if they did not honor the spirits, witches and goblins that ran free that night, leaving them offerings such as food or candy, these spirits would cause them harm.

On the other hand, not all elements of Halloween and horror come from fantastic elements; in many cases, medical conditions, pharmacological or toxicological reactions can explain cases that at the time were interpreted as supernatural events.

In addition to this, cinema and literature, as a complement to this festivity, have occasionally been inspired by real medical facts to create the horror stories that accompany us every October. Vampires, witches, werewolves and even modern movie characters, such as Freddy Krueger from Nightmare on Elm Street, can be explained from a medical perspective.

Triki Triki_lch

Vampire: ¿monster or disease?

Since its first descriptions, the idea of vampires has fascinated mankind. It has been represented in diverse ways in oral tradition, literature and cinema; however, it maintains common characteristics in all of them. Although the best known representation in the West is Count Dracula from Bram Stoker’s eponymous novel, African and Eastern folklore also have vampires, such as sasabonsam from West Africa and manananggal in the Philippines.

Considering the global distribution of this myth, and assessing its characteristics from a medical perspective, similarities have been described with some rare medical conditions, especially with a hematological disorder, porphyria.

The term porphyria is used to name a group of disorders characterized by defects in the enzymes involved in the synthesis of the heme group (an essential structural element of hemoglobin and other proteins in the body). According to the enzyme affected, there are several subtypes of the disease, such as porphyria cutanea tarda, acute intermittent porphyria and congenital erythropoietic porphyria.

The signs and symptoms of congenital erythropoietic porphyria are the ones that have been most associated with vampire lore, as it is characterized by great photosensitivity and severe skin damage from sun exposure, described in the mythical vampires as sun aversion, or destruction by the sun; This causes severe scarring and deformities in the photoexposed areas, the skin of the lips and the mucosa of the gums tightens in such an extreme way that the teeth appear more prominent, like fangs. Patients also present chronic hemolytic anemia, which explains the continuous need to consume blood in the legends. Even the aversion to garlic, commonly used as a defense against vampires, is explained by the ability of some compounds of this plant to induce the degradation of the heme group, which worsens the anemia in the patients.

Vampiro halloween

Other rare diseases that have been associated with legendary descriptions of vampires are pellagra, rabies and hypohidrotic ectodermal dysplasia. In pellagra, caused by niacin and tryptophan deficiency, patients present with high photosensitivity; in addition to tongue erythema and dementia, which manifests with insomnia and aggressiveness. Rabies virus infection, its transmission by bites from animals linked to the vampire tradition such as bats, dogs or wolves, and some of its symptoms such as hydrophobia, aggressiveness and insomnia, is another example. Patients with hypohidrotic ectodermal dysplasia have congenital decreased sweating ability, thin skin and hair, prominent bluish dark circles under the eyes, heat intolerance and small pointed teeth; all these particularities are related to the physical description of vampires.

Given the infrequency of these diseases, the various symptoms not explained by diseases known at the time, the vampire myth was able to feed on descriptions of these patients, giving a supernatural interpretation to real ailments.

Witches: myth, magic and reality

The image of witches and their representation throughout history has changed in numerous instances. From evil, ugly, wicked women with hooked noses and full of warts over a boiling cauldron, to teenagers of hegemonic beauty learning to control their powers, the witch has been in the collective imagination even since the Old Testament. 

However, the real history of witches is much darker and, in the case of women accused of being witches, often fatal. Although most of them were simply healers or wise women, gifted with botanical knowledge, they were seen as pagans doing the work of the “devil”. This is why in the Middle Ages mass hysteria against witches invaded Europe and many of them were executed at the stake or by hanging. 

In fact, although many of the “potions” and ointments used by the witches had no real effectiveness, some of the medicines used by the facultative medicine have their origin in the cabinet of these women.

Bruja halloween_lch
Willow bark, used for inflammation, contains salicin, which later gave rise to salicylic acid, the active compound in aspirin. Purple foxglove (Digitalis purpurea) was a base ingredient in potions used to treat “dropsy”, a term given to swelling and congestion in patients with heart disease; from this plant originated drugs used in heart failure, such as digoxin and digitoxin. One of the most famous cases of persecution and trial against witches is the Salem Witch Trials in Massachusetts, United States, in 1692, where the Puritan culture of the time catalyzed another instance of mass psychosis that began with two girls who suffered convulsions, body contortions and uncontrolled screams. After more young girls had similar symptoms, three women were accused of witchcraft. This eventually led to the indictment of about 150 people and the execution of 18, 12 women and 6 men. Among the interpretations suggested to explain the Salem “witchcraft” cases are hysteria or fraud. On the other hand, one of the theories that has gained strength is ergotism as the cause of the symptoms presented by the young women. Ergotism is caused by ergot, Claviceps purpurea, a member of a family of fungi that contaminate cereals and from whose alkaloids multiple pharmacological and hallucinogenic compounds have been isolated, among them ergotamine and lysergic acid (from which LSD derives). The ingestion of rye bread contaminated with Claviceps purpurea gives rise to two clinical syndromes, gangrenous ergotism and convulsive ergotism, the latter being the one that can be associated with the symptoms described at the onset of persecution in Salem, since it presents with hallucinations, painful muscular contortions, delirium and paranoia. The effects of ergot were not known to the American medical community in the 17th century, so the physicians who examined the young women initially found no explanation for their symptoms, mistaking them for witchcraft. In the case of witchcraft, both sick people and healers were taken as supernatural beings, or as evil women with demonic pacts, as there was no explanation for their knowledge or symptoms at the time.

Werewolves: folklore versus genetics

Werewolves have been an essential part of legends since ancient times; in tradition they are people who transform into wolves without completely losing the ability to think like humans. Depending on the stories, it has been seen as punishment, curse or inheritance. Science has tried, as in the cases previously described, to explain the logical or scientific basis of these beings, highlighting some conditions that have contributed to the werewolf legend, such as infection by the rabies virus, the porphyria already discussed and some psychiatric diseases in dissociative states (9). However, the human condition that has been most closely linked to the werewolf legend, so much so that it has been called “werewolf syndrome,” is congenital universal hypertrichosis.

Congenital hypertrichosis is a rare genetic disorder characterized by excessive hair growth all over the body, including the face. These people have inherited mutations in some genes that control the growth of hair follicles.

Fewer than 50 cases have been described in history; one of the first in 1556, in a slave from Tenerife who was brought to the French court; two of his sons inherited and passed on the condition. Throughout history, people with hypertrichosis were exhibited as rarities in circuses and courts, and further fueled the werewolf legend.

Lycanthropy, which is not associated with congenital hypertrichosis, is a mental disorder in which the patient believes he/she is a wolf or some other beast; it is a dissociative state that can be associated with psychiatric illnesses such as schizophrenia, depressive or manic psychotic states, and ingestion of some hallucinogenic alkaloids.


Dying in your sleep: cinematic terror inspired by real events

The idea of the villain Freddy Krueger, from Nightmare on Elm Street, who can kill in his sleep, has tormented movie fans since the release of the first film of this saga in 1984. However, the astonishment is greater when it is known that Wes Craven, creator and director of this story, was inspired by events that made news a few years earlier about deaths associated with nightmares. This inspiration apparently arose after the news report in 1981 of the death in dreams of 18 young people, part of a group of apparently healthy immigrants from Laos, who according to sources at the time “screamed in their sleep and then died”. According to Craven, one of the stories that most inspired the creation of Freddy Krueger had to do with a refugee family, who had escaped from extermination camps in Hmong; their teenage son had nightmares and told his parents that he was afraid to sleep, because what was chasing him in his dreams could catch him, and he tried to stay awake for days. When he finally fell asleep, his parents were awakened by screams in the middle of the night; upon arriving in his room the young man had died during a nightmare. In the 1980s, the number of such deaths grew alarmingly among immigrants from Southeast Asia, coming to be called “Asian death syndrome” and later “sudden unexpected nocturnal death syndrome”. On post-mortem examination of the first 18 patients, all had enlargement of the heart (cardiomegaly) and 17 of them had alterations in the cardiac conduction system, the electrical system that allows the heart to beat. Subsequent studies concluded that these patients had what in 1992 was called Brugada syndrome, a genetic defect of the conduction system that alters the heart rhythm and is associated, in untreated patients, with sudden death, sometimes during sleep. In this case, a medical mystery, which at the time had not been solved, gave rise to a terrifying fantasy, which continues to feed our nightmares. 
** As we can see, the legendary elements of horror can be associated with real and scientific facts, which our imagination transforms into legends. What other fantastic elements do you think can be associated with real medical events?


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