[The remarkable debate during the beginning of the nineteenth century concerning the aetiology of scabies].

The scabies mite (acarus or sarcoptes scabiei) was known already to Aristoteles, to the Arabic medicine during the early and to European physicians as well as laymen during the later Middle Ages, depicted in 1687 by Bonomo in Italy and by Schwiebe in Germany during the beginning of the eighteenth century. Later in the middle of the century three pupils to Linnaeus in their doctor's theses stated that the scabies mite (Acarus humanus subcutaneus) was the cause of scabies. The best pictures of the scabies-mite as well as of the flour- and cheese-mite was given by the Swedish entomologist Charles de Geer in 1778. In spite of all these facts the real aetiology of scabies seemed to be unknown in France and in most parts of Europe. This was probably due to the fact that no one had learned the rather simple method to extract the mite from the skin with a needle and thereby verify its existence. In the beginning of the twentieth century scabies was a real problem for the health authorities. In Paris l'Académie de Médecine even offered a reward to the person who could solve the enigma of the itch. Jean Chrysanthe Galés was the pharmacist at l'Hôpital St. Louis, the famous skin hospital in Paris, where at this time about 65 percent of the beds were occupied by patients suffering from scabies. Galés also studied medicine and wanted to write a doctor's thesis. As the theme of a dissertation he was given the cause of the itch. In 1812 he published his thesis ("Essai sur la Gale") including a plate with sketches of mites that he claimed to have extracted from vesicules on the skin of his scabies patients. His findings could not be verified by other investigators. Galés however refused to take part in any control experiments and left the hospital. The debate concerning the supposed cause of the itch continued for two decades both inside and outside the hospital. F.C. Raspail, a famous natural scientist, was interested. After having studied the literature and especially the drawings by de Geer he was convinced that the mites depicted by Galés were similar to de Geers' flour-and cheese mite and that they had no resemblence to his picture of scabies-mite. In a control experiment Raspail could show how Galés had cheated by contaminating his slide with cheese-mites. However, a Corsican student at l'Hôpital St. Louis named S.F. Renucci knew the answer to the riddle. He had long ago been taught by peasant women of his home island how to extract the mite and he could now show the method to the doctors at l'Hôpital St. Louis. this was on August 13 in 1834, which usually in the literature is looked upon as the day when the discovery of the aethiology of scabies was made. Maybe we have a different view in Sweden.