482 DISEASES OF THE SKIN 



(6) Bouffard's white mycetoma. 

 Parasite, Indiella somaliensis, 1905. 



The sclerotia occur as hard, small, spherical and polyhedral 



grains. 



It destroys bone. 



(7) Musgrave and Clegg's white mycetoma. 

 Parasite, Nocardia asteroides, 1890. 



The sclerotia are first oval, then vary in shape. 

 It invades the medulla of bone. 



(C) The Red Group. 



Pelletier's red mycetoma. 



Parasite, Nocardia pelletieri, 1906. 

 It may attack other parts of the body. 

 It occurs in Africa. 



TREATMENT. 



Amputation is the most certain cure, well above the ankle or wrist, 

 rarely less than this. 



Scraping and cauterizing with potassium iodides internally may be 

 successful in some cases. 



MYIASIS. 



The invasi(jn of the skin or other parts by the larva? of flies. 



(1) Dermatobia cyaniventris (Oistridae). 



This is found in Tropical America, and is present in cattle, 

 pigs, dogs, monkeys, birds, and rarely in man. 

 There is local pain, itching, swelling, oedema with a central 

 sinus, in which the larva may be seen from time to time. 

 The larva may attack any part. 



(2) Cordylobia anthropophaga (Muscid^e). 



It is common in Africa, where it is known as Tambu fly disease. 



In Europeans the thighs and buttocks are usually affected, the 



source of infection probably being the latrines. 



In natives, the forearms, axillae and head are more commonly 



attacked. The inflamed area is about three-quarters of an inch 



in diameter. 



Extract the larva and treat antiseptically. Some require a long 



time to heal. 



(3) Chrysomyia macellaria (Screw-worm). 

 Common in America. 



The insect lays a mass of 300 to 400 eggs on the surface of 

 wounds, in the ears and nasal fossas of persons sleeping in the 

 open air. Offensive discharges will attract the flies. 



