SCABIES 



2217 



cotton moth {Gelechia gossypiella). The mite attacks people; it 

 attaches itself to the skin by its sucking discs and claws, and prob- 

 ably injects some irritaing substance into the skin while attempting 

 to obtain nourishment. 



Symptomatology. — The mite causes an urticarial and papuloid 

 eruption on the breast, arms, face, neck, and shoulders of persons 

 handling corn and barley, or cotton seed, which has no tendency to 

 spontaneous cure while the people continue to handle the infected 

 grain. The symptoms begin after an incubation of twelve to sixteen 

 hours with itching and the appearance of wheals surmounted by 

 vesicles, which are usually about the size of a pin's head. These 

 vesicles may at times pustules in a few hours. Severe cases show 

 febrile symptoms, vomiting, and albuminuria. 



Diagnosis.— The presence of an eruption somewhat resembling 

 lichen urticatus in people handling grain or straw or cotton seed, 

 or sleeping on new straw mattresses, should always arouse suspicion 

 of the presence of this mite, and search for it should be made in the 

 grain or straw or cotton seed. 



Treatment. — The treatment consists in removal of the cause — 

 i.e., of handling the infected grain — and the apphcation of soothing 

 lotions, such as calamine lotion, or a dilute carbolic acid or acetic 

 acid lotion. 



Scabies. 



Synonyms. — Scabrities, Psora (term wrongly apphed). Itch, 

 Courap (=itch Bontius), Scabies indica (Sauvages), La gale 

 (French), Kraetze (German), Sarna (Madeira), Scabbia (Italian). 



Definition. — Scabies is an infection of the superficial layers of the 

 skin by the female of Sarcoptes scabiei var. hominis (Linnaeus, 175S), 

 which, making a minute opening into the horny layer, forms a 

 burrow more or less parallel to the surface, and in so doing causing 

 itching. Secondary lesions are vesicles (of which the most typical 

 is at the far end of the burrow, immediately beyond which lies the 

 acarus), scratches, scabs, pustules, and a superficial dermatitis. 



History. — Aristotle appears to have known the itch insect, but if this is true 

 the knowledge was lost, and certainly Avenzoor in the twelfth century deserves 

 the credit for discovering or rediscovering it. Scaliger, in 1557, described it 

 as being globular in form and so minute as to be scarcely perceptible. He says 

 that the people of Turin called it scirro, while in Gascony it was known as 

 hrigant. He also described the burrows, and in ' Exercitatio 194, de Subti- 

 libus,' numero 7, he states that when extracted it shows a certain amount of 

 movement, and when crushed between the nails causes a slight noise and 

 emits a little fluid. After this it was described by Ingrassius of Naples, by 

 Gabucinus, by Jobertus, by Aldrovandus, but more especially by Mouffet 

 in his' Insectorum,' completed in 1589. In 1654 Hauptmann, who called the 

 acari ' Reitleisen,' published the first figure of the mite in 1654 and again in 

 1657. He was followed by Haffenreffer in 1660, by Heintke in 1675, who gave 

 extraordinary illustrations of the arachnid, and by Ettmuller in 1682, whose 

 illustrations are recognizable. In 1683 Bonomo and Cestoni published their 

 letter to Redi on the subject, and in 1702 this communication was read by ^ 

 Mead before the Royal Society,and published in the Philosophical Transactions. 

 Bonomo described and figured the egg. He was followed by Morgagni in his 

 tittv-fifth letter, Book IV., by Bonanni in 1691; by Linnaeus in 1767, who 



