How a Medieval Physician Treated Leprosy: Guy de Chauliac's Advice

In 1363, at the papal court in Avignon, a physician of about sixty finished the book that would make his name. Guy de Chauliac held the highest medical degree of his day, a mastership from the University of Montpellier, and he had studied at Bologna and Paris before entering the service of three popes in turn: Clement VI, Innocent VI and Urban V. He called his book an inventory or collection of surgery. Later printers in Venice named it the Chirurgia magna, the Great Surgery, and it was read, copied and translated for centuries. Guy died in 1368.¹

Tucked into its sixth treatise is a chapter on leprosy. It is one of the clearest windows we have onto how a learned medieval doctor thought about the disease: what caused it, how to tell whether a frightened neighbor had it, and what could be done. The answer to the last question is the reason the chapter is worth reading closely, because Guy’s honest reply was that not very much could be done, and he wrote a long regimen anyway.

A note on words. Medieval writers used “leprosy” (in Latin lepra, in French ladrerie) for a condition defined by signs and humoral theory, not by a bacterium. Some people so diagnosed would have had what is now called Hansen’s disease; others probably had other skin or nerve conditions, such as the eczema and scabies of poverty.² Historians such as Carole Rawcliffe have stressed the danger of reading modern categories and attitudes back into the period.³⁴

A disease of the whole body, in humoral terms

Guy explained leprosy through the medicine of Galen and Avicenna, the standard authorities of the medieval universities. In his account it was a profound failure of the body’s power to turn nourishment into healthy flesh. An overheated liver burned the blood and turned it toward melancholy, or black bile. When that spoiled blood reached the limbs, it could not become sound red flesh, and the form of the body was corrupted throughout.¹

His school, he said, recognized four kinds of the disease, one for each humor that could be burned into melancholy: elephantia from melancholy, leonina from choler, tyria from phlegm and alopecia from blood. In practice, he added, they were rarely found pure. The outside causes he listed were corrupt air, contact with people who had the disease, bad food and inheritance, with contributing factors such as suppressed menstruation or hemorrhoidal bleeding and weakness of the spleen.¹

None of this was new with Guy. More than a century earlier the English physician Gilbertus Anglicus had written a long chapter on leprosy that defined it as black bile dispersed through the whole body, listed causes from foul air and bad diet to the breath of a sick person, and described the same four varieties. Henry Handerson, who summarized Gilbert’s Compendium in a study published in 1918, quotes the historian Kurt Sprengel calling the chapter “almost the first correct description of this disease in the Christian West.” Gilbert’s notes on numbness of the fingers and toes, loss of eyebrows and hoarseness show close observation, even inside a humoral framework.⁵

Guy also drew on a teacher closer to home. He credits “maistre Iordain en Montpellier” (Master Jordan at Montpellier) with distinguishing a “disposition” to leprosy from the disease in “act,” which ran through stages of beginning, increase, full state and decline.¹ The edition read does not identify Jordan further. A physician named Jordanus de Turre, active between about 1313 and 1335, wrote on the treatment of leprosy, and the historian Luke Demaitre has devoted a study to that writing under the title “The relevance of futility.”⁶

The examination: a wrong verdict was the first danger

By Guy’s time, deciding who had leprosy had become a medical task. Demaitre’s research, as summarized by one reviewer, shows priests long taking the lead, with learned physicians moving to the center only in the second half of the thirteenth century, armed with checklists of signs.²⁷ Guy’s chapter is such a checklist, with a procedure attached.

He divided the signs into two groups. “Univocal” signs always meant leprosy, and most of them were on the face: rounded eyes and ears, thinned and thickened eyebrows, nostrils widened and twisted outside but narrowed within, misshapen lips, a hoarse voice that seemed to come through the nose, bad breath and a fixed stare. “Equivocal” signs could appear in other diseases too, and he listed sixteen, from hard nodules on the joints and loss of hair to wasting of the muscle at the thumb, numbness, gooseflesh, and skin on which poured water seemed to run off as if oiled. Some items were moral judgments rather than symptoms, such as being cunning or trying to mix too much with other people.¹ A modern reviewer of Demaitre’s book notes that several of Guy’s signs, such as scabies, foul breath and bad dreams, have more to do with poverty and its effects than with any particular disease.²

Then comes Guy’s central warning. In examining suspects, the physician must be very careful, “car c’est très grande injure de séquestrer les non sequestrables, et de laisser les ladres auec le peuple” (“for it is a very great wrong to separate those who should not be separated, and to leave the sick among the people”). He told the examiner not to judge by a single sign but by several agreeing together, especially the univocal ones.¹

The procedure he laid out was long. The examiner was first to comfort the person, saying that if they had the disease it would be a purgatory for the soul, and that the world might hate them but God did not; if they did not have it, they would be left in peace. They were to swear to answer truthfully about family history, contact with sick people, diet and past illnesses, and acquaintances could be questioned too. The physician took the pulse, let blood and examined it, washing it to see whether gritty grains remained. Some further tests on the blood with salt, vinegar and urine he allowed as a formality. The patient was sent away and returned in the morning with urine. Then came a close look at the face, and an examination of the whole body undressed, including pricking the back of the heel and the leg to see whether the person could feel it and say where.¹

The verdict had four possible outcomes. A person showing only a disposition and a few faint signs was quietly told to keep a good regimen and take medical advice. One with many equivocal signs but few univocal ones was to be warned firmly to live carefully and stay mostly at home. Only someone with many signs of both kinds was to be separated, with kind and consoling words, and taken to the leprosarium. Anyone found healthy was to be cleared and sent back with physicians’ letters to the “Recteurs,” the local rectors (which the sixteenth-century translators glossed as rectors or parish priests).¹ Rawcliffe’s study of England, as described by François-Olivier Touati, likewise found that diagnoses “were not pronounced lightly,” with careful examinations by priests and physicians and formal judgments recorded from 1227.³

Prevent, cure, palliate

On the outlook, Guy was blunt. Everyone agreed, he wrote, that the disease was very grave, hereditary and contagious, and almost impossible to remove once confirmed. He repeated Avicenna’s argument: if a localized cancer cannot be cured, how can a “cancer” of the whole body? His conclusion was “Il peut bien estre preserué, et pallié” (“it can well be prevented and relieved”), but not cured.¹ Demaitre’s reviewer reports the same standard verdict for the period: leprosy was then not curable.²

So Guy organized treatment into three regimens. For those merely disposed to the disease, the aim was prevention: moderation in air, food and drink and the other “non-naturals” of medieval hygiene; purges two or three times a year, especially in spring and autumn; bloodletting; small cautery wounds kept open on the arms and legs to drain humors; and electuaries and dressings to strengthen the liver. For the disease in its early, unconfirmed stage, the aims were a cooling and moistening regimen, evacuation of the burned humors by bleeding, purges, baths, cupping and rubbing, and medicines thought to correct the damage, including viper preparations and cordial confections. For confirmed disease, the goals were palliative: to keep the body moist with milk and chicken broth, to strengthen the heart with cordial electuaries, and to keep the limbs from deforming, along with cosmetics to improve the appearance of the face.¹

Guy then admitted that these matters belonged more to the physicians than to surgeons like himself, whose role was to judge and to operate, and he sketched the details only briefly, in eight short sections.¹

Milk, baths and vipers

Some of the regimen is gentle. Patients were to follow the diet for melancholic conditions and avoid sex and anything heating. Milk, after Avicenna, was among the most suitable foods, drunk fresh from the animal, and Guy says that living on it alone would be good.¹ Demaitre’s reviewer notes that for centuries similar advice was given to avoid salty, acidic and spicy food and extremes of heat and cold.²

Bleeding from large veins was not for confirmed cases, Guy wrote, unless the patient was very full of blood or there was fear of constricted breathing; cupping and scarification suited them better. He reported that Rhazes, the Persian physician, claimed to have restored a young man whose face had begun to form nodules and whose hair was falling out, by bleeding him and then purging him again and again, more than forty times in five months; after six more months of good regimen he was said to be fully well.¹ There is no way now to know what that young man had.

After purges came herbal drops for the nose, steam baths and washes. The patient’s head was shaved, the body rubbed with a herbal decoction and then anointed with hare’s blood, followed by a dose of theriac, the many-ingredient antidote, in wine. A later ointment included snake fat.¹

The most famous ingredient was the viper. Guy cites Avicenna for the view that viper flesh was among the best medicines for leprosy, and Galen for five supporting cases. His instructions describe choosing black-backed snakes from dry places, removing the head and tail, skinning and washing them, and cooking the flesh with fennel, dill and bread, so that the patient drank the broth and ate the meat. The flesh could also go into a sweetened dish, a pie or an electuary, or live snakes could be steeped in wine at the grape harvest; following an authority he calls Henric, the beheaded snakes could be distilled into a water, and patients could be washed with the water of their decoction. Guy expected the body to swell and then shed scales, and said the course should stop when the patient’s sight dimmed and thinking became confused, an observation that suggests the treatment was hard on patients.¹ Readers interested in other medicines made from bodies may compare early modern corpse medicine.

Cautery came last. Guy noted that Albucasis had recommended seventy burns, on the theory that more was better, but he wrote that he was accustomed to use only small, round point cauteries on the arms, legs, groin, armpits, crown and back of the neck.¹

What the regimen tells us

It would be easy to read Guy’s chapter as a catalog of futile cruelty, and some of it was hard to endure. But it is also a careful document. It insisted on evidence before separation, offered quiet advice rather than exclusion to people with doubtful signs, and aimed, in confirmed cases, at comfort. Demaitre’s reviewer concluded that where cure was impossible, physicians “did their palliative best” for their patients.²

Recent scholarship has also revised the picture of what separation meant. Touati summarizes Rawcliffe’s finding that about 320 leprosy hospitals have been identified in England, and that “Life in the leper-houses, far from being one of exclusion, reveals varied degrees of isolation and considerable involvement in social and economic life outside.” Residents were often seen as embodiments of the suffering Christ.³ At the hospital of St. Mary Magdalen near Winchester, isotope analysis of adolescents with skeletal signs of leprosy, buried there between the ninth and twelfth centuries, long before Guy wrote, found that seven of the nineteen had come from further afield, some possibly from outside Britain, which suggests they traveled there for care. The researchers conclude that “leprosy stigma, as we understand it today, may not have existed in this time and place,” and they link the familiar story of expulsion to more recent colonialist narratives.⁸

What Guy lacked was a cause and a cure. Today leprosy, also called Hansen’s disease, is known to be caused mainly by Mycobacterium leprae. It affects the skin and peripheral nerves, is believed to spread through prolonged close contact with untreated cases, not through casual contact, and still produces about 200,000 new cases a year. The World Health Organization’s statement is simple: “Leprosy is curable with multidrug therapy (MDT),” which WHO provides free. The same fact sheet notes that people affected still face stigma and discrimination, which is one reason the history of how they were examined and treated matters.⁹

Footnotes

1. Guy de Chauliac, La grande chirurgie, ed. Nicaise (1890), VI.1.2 “De ladrerie,” pp. 401-412; introduction (biography and edition). ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴ ↩¹⁵ ↩¹⁶

2. Schmitt 2007, review of Demaitre, Leprosy in Premodern Medicine. ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶

3. Touati 2009, review of Rawcliffe, Leprosy in Medieval England, Medical History 53: 150-151. ↩ ↩² ↩³

4. Rawcliffe 2006 (catalog record). ↩

5. Handerson 1918, chapter on Gilbert’s Compendium, section on De lepra. ↩

6. Demaitre 1996, Bulletin of the History of Medicine 70 (PubMed record). ↩

7. Demaitre 2007 (catalog record). ↩

8. Filipek et al. 2022, abstract and introduction. ↩

9. WHO, “Leprosy” fact sheet. ↩