274 SKIN INFECTIONS. 



similar to S. pyogenes aureus. It is probably only a virulent aureus. 

 It has been described under the name of Diplococcus pemphigi con- 

 tagiosi. 



The Staphylococcus epidermidis albus, or stitch abscess coccus, is 

 considered by Sabouraud to be the cause of eczema seborrhoicum. 



It is in scrapings from the skin of lepromata that we find acid-fast 

 organisms in the greatest profusion. In tuberculosis of the skin the 

 tubercle bacilli are exceedingly scarce. Inoculation of a guinea-pig 

 will probably give positive results with the tubercle bacillus. The 

 leprosy bacillus is noncultivable and noninoculable for experimental 

 animals. 



Anthrax and glanders cause skin lesions which can only be surely 

 diagnosed culturally or by animal inoculation. 



Plague bacilli may be isolated from the primary vesicles appearing 

 at the site of the flea bite. 



Tropical phagedaena is thought by some to be due to a sort of 

 diphtheroid organism. 



The skin diseases due to fungi are discussed under that section. 

 Of the skin affections caused by animal parasites, ground itch is the 

 most important. This is a form of dermatitis due to the irritation set 

 up by the hook-worm larvae penetrating the skin of the foot and leg. 



The Sarcopsylla penetrans or jigger (sand flea) is an important agent 

 in ulcerations about the foot. 



Certain acarines cause skin lesions, as is also the case with the larvae 

 of certain flies. 



The itch mite (Sarcoptes scabiei) is an important animal parasite 

 of the skin. 



The various lice, fleas and bed-bugs are well understood as causes 

 of skin irritation. 



Filarial infections are also important. 



