ACARINE DERMATOSES 



2215 



5. scahiei var. equi in the horse; S. scahiei var. suis in the 

 pig; S. scahiei var. auchenicB^m the lama; S. scahiei var. 

 cameli in the camel. 

 Notoedres cati var. Hering, 1838, found in cats, may occur 

 in man. 



Demodicid^. 



Demodex folliculoyum Simon, 1842, is said to be the cause of 

 certain inflammations in seborrhoea. Some authors con- 

 sider them to be of importance in the carriage of certain 

 diseases, such as leprosy and cancer. 



Rarer AcarincB, which attack man occasionally, are Tromhidium 

 striaticeps Heim and Oudemans, 1904, on fowls and dogs ; T. ameri- 

 canum Riley and T. irritan ; Metatromhidium poriceps Heim and 

 Oudemans, 1904, on fowls and dogs; Microtromhidium meridionale 

 and M. pusillum Hermann. 



Copra Itch. 



Definition, — A very pruriginous dermatitis, found in people 

 handling copra, and caused by Tyroglyphus longior Gervais ,var. 

 castellanii Hirst (p. 729). 



Historical and Geographical. — This dermatitis was described by 

 Castellani in 1911, who observed it in Ceylon in people handhng 

 copra, and considered it to be due to an acarus-like parasite, swarm- 

 ing in many samples of copra. He sent the specimens of the para- 

 site to Hirst, who described it as a new variety of Tyroglyphus — 

 Tyroglyphus longior Gervais var. castellanii Hirst. 



Castellani's researches have been recently confirmed by Graham 

 Little, Whitfield and Ditlevsen. 



.ffitiology. — The 

 mite is present in 

 huge numbers in 

 certain samples of 

 copra, and may occa- 

 sionally be found on 

 the skin of the 

 patients, but remains 

 on the skin only 

 temporarily, as it yig. 8yo.- — ^Microphotograph of the Tyrogly- 

 does not bury itself. phus of Copra Itch. {X40,) 



It apparently induces 



the dermatitis in the same manner as Pediculoides ventricosus 

 Neuport, which lives in diseased cereals, produces an eruption in 

 persons handling such cereals. 



Experimental Reproduction. — When copra dust containing the 

 mite is rubbed into the skin, itching frequently begins very shortly 

 after, and twenty-four to forty-eight hours later an extremely 

 pruriginous urticarial or papuloid eruption often develops. The 

 same result is obtained by picking the mites out of copra dust and 



