I am fascinated by historical mysterious diseases that appear suddenly and then strangely disappear.

One such example is "sweating disease." It first reared its ugly head in England in summer 1485, and there were outbreaks in 1508, 1517, 1528 and 1551 before it disappeared, never to be seen in that land again. It was highly contagious and took thousands of lives around England.

Sweating illness caused shock and horror because of the sudden onset and lethality.

According to physicians at that time, the symptoms of sweating disease included great sweating and stinking; fever; redness of the face and body; continual thirst; breathlessness; back, shoulder, stomach and extremity pain; myalgia; headache; cardiac palpitations; and a desire to sleep. One chronicler recorded that people were throwing off their bedclothes and running through the streets of London seeking relief from fever. Others treated their thirst with cold drinks, but there was no treatment for the foul-smelling perspiration. Barely 1 in 100 escaped death, and those who survived 24 hours after the sweating ended were not free from the disease. They continually relapsed and subsequently perished. What was shocking was the speed at which it killed the victims. An excellent review of the disease is contained in “Sweating Sickness: In a Nutshell,” a book by Claire Ridgeway.

Another strange disease occurred during World War I. The first patient identified was afflicted with prolonged sleep. At first, the treating physician, Dr. Cruchet, wondered if the symptoms could be the aftereffects of mustard gas or even a new chemical weapon. Other patients soon followed, and in all, Cruchet saw 64 similar cases with no standard diagnosis.

What was striking about these patients was the unusual range of symptoms. Some had fever; others did not. Most complained of headache and nausea. Strangest of all was how much these soldiers slept. It would have seemed almost serene at first — blank, expressionless faces, free of terror and pain, calmly asleep in row after row after row. What was frightening about these men was that they would not awaken. It must have felt like being in a room full of the breathing dead.

At first, their symptoms vaguely matched any number of diseases, but as they progressed, they did not follow the course of other diseases of the trenches. The soldiers were not comatose; they were simply asleep. Cruchet spent several months studying the sick soldiers, and he prepared a paper on the unusual cases he found coming from the trenches in Verdun. He did not know that on the other side of the war another physician was witnessing the same. That physician, in a clinic in Vienna, was preparing a similar paper on the same subject. Though the two men could not coordinate their efforts, or even contact each other, they were witnessing the same disease. By definition, that made it an epidemic and in fact, specifically described as "the forgotten epidemic." It remains one of medicine's greatest mysteries and is characterized brilliantly in Molly Caldwell Crosby's book “Asleep.”

One other disease appeared to be limited to the rural population of Yugoslavia, Rumania and Bulgaria. It was first reported in the New York Times on Dec. 4, 1966. The disease affected 25 percent of the inhabitants and is almost unknown in any other region. It strikes the young, teenagers or even children under 10 years of age. As the disease develops, the sufferers become anemic and greatly weakened. In the advanced stage it is often fatal. Evidence seemed to indicate that it was connected in some way with the rivers in the region.

The strangest of all may be the Dancing Plague of 1518. The events took place in Strasbourg, France. A woman began to dance fervently and without pause. She carried on for almost six days, unable to stop. When she finally did, the dancing had spread throughout the city. Within a week, nearly 40 people were uncontrollably dancing in the street. By the end of the month as many as 400 individuals were taking part in this remarkable, bizarre outbreak and dozens died from exhaustion or exposure.

Max Sherman is a medical writer and pharmacist retired from the medical device industry. He can be reached by email at  maxsherman339@gmail.com.