PIEDRA 



2IOI 



Guiana natives consider it to be due to bathing in certain white 

 or milky waters, while it does not occur if they bathe in the brown 

 peat bush waters. 



Symptomatology.- — The hair of the head of women, and less fre- 

 quently the hair of the head and beard of men, is affected. The 

 affected hairs present strings of pin-head-sized nodosities, which 

 are better felt than seen. The nodosities may be very numerous, 

 and are found on the surface of the hair-shaft, either on one side or 

 surrounding it like a sheath. They are black and hard, though not 

 so hard as the name piedra (stone) would imply, and a kind of 

 crepitation is produced when the hair is combed. There is often 

 matting and knotting of the hair. The disease is chronic, and the 

 nodosities do not disappear spontaneously. 



Horta has described a variety of piedra in Brazil, characterized by the 

 nodules containing large cyst-like structures, which Pinoy considers to be 

 probably asci (seep. 1102). 



Diagnosis. — The microscopical examination of the nodosities 

 renders the diagnosis easy. 



Prognosis. — The affection is of long duration, and has no tendency 

 to spontaneous cure. 



Treatment. — This is difficult. It has been recommended to apply 

 a 5 per cent, salicylic alcoholic solution or benzene and turpentine to 

 the hair, and to wash the head regularly with a perchloride lotion 

 (i in 2,000). In obstinate cases it is necessary to shave the head. 



Trichosporosis indica. 



In India and Ceylon a condition, similar to piedra is occasionally observed. 

 It is, however, much less severe, a few minute nodules only being present 

 on the hairs of the beard and moustache, and the hair of the scalp being 

 rarely affected. The fungus seems to be different from that of the Columbian 

 piedra. 



Trichosporosis of Temperate Zones. 



Cases of trichosporosis of temperate zones or piedra nostras (tinea nodosa) 

 have been described by Biegel (1869), Caro, Behrend, Unna, Pick, Vuillemin. 

 The nodosities in such cases have been found on the hairs of the moustache 

 and beard, not on the hairs of the head. The fungi are slightly difEerent from 

 Trichosporum giganteum. Several species have been described- — Trichospomm 

 beigeli Rabenhorst, 1867, T. ov aides Behrend, 1890, T. ovale Unna, 1896. 



TRICHOMYCOSIS FLAVA, RUBRA, NIGRA. 



Synonyms.— Trichomycosis axillaris, Trichonocardiasis, Tropical 

 lepothrix, Castellani's Trichomycosis, Trichomycosis chromatica, 

 Chromotrichomycosis. 



Definition. — A nodular affection of the hair, usually of the axillary 

 regions, caused by Cohnistreptothrix tenuis Castellani [Nocardia tenuis 

 Castellani), either alone or in symbiosis with chromogenic cocci. 



Historical. — Nodular affections of the hair have been described 

 by European observers under various names, such as Lepothrix 

 (E./ Wilson), Trichomycosis nodosa (Patterson), Trichomycosis 

 palmellina (Pick), but a great deal of confusion has existed until 



