2IOO 



TROPICAL DERMATOMYCOSES 



have been obtained by using chrysarobin (chrysarobin, gr. x. to xxx. ; 

 ung. zinci ox., §i.). This must be appHed cautiously. When th ; 

 malady affects large tracts of the body, only a portion should be 

 treated at a time, to prevent as far as possible symptoms of absorp- 

 tion. The urine should be regularly analyzed during the treat- 

 ment. The chrysarobin ointment must not be apphed to the face, 

 lest a severe conjunctivitis should develop. For the face a resorcin, 

 or resorcin-sulphur, or resorcin-salicylic, or salicylic acid ointment 

 (resorcini, gr. xxx. to 3i. ; ac. salicylici, gr. xv. ; vasehne, §i.), is 

 advisable, or citrine ointment may be used. 



Montoya recommends chrysarobin dissolved in chloroform (chrysarobin 

 ID parts, chloroform 90 parts). Apply with a fine brush, "When dry, apply 

 gutta-percha dissolved in chloroform (gutta-percha 10 parts, chloroform 

 90 parts) . 



Chrysarobin may conveniently be applied in the form of a vernisol varnish 

 ( 5 to 10 per cent.). 



PIEDRA. 



Synonym.- — Trichosporosis Tropica. 



Definition. — Piedra is a mycotic disease of some parts of South 

 America causing very hard, small nodosities on the hair. 



Historical and Geographical. — The condition has been known 

 locally in Columbia since remote times, but the first scientific 



descriptions are due to Desenne 

 (1878), Morris (1879), Osario, and 

 Megalhaes. More recently the 

 condition has been studied by 



Fig. 842. — Piedra. 



Juhel Renoy, Fernet, J. M. H. 

 MacLeod, Horta, and others. 

 This disease of the hair is com- 

 FiG. 841.— Transverse Section mon in some districts of Columbia, 

 THROUGH A PiEDRA NoDULE. cspccially thc vallcy of Canca; 



but closely alHed conditions are 

 observed in several parts of the tropics, and occasionally in 

 temperate zones {piedra nostras). 



iEtiology.— If an affected hair is washed in ether, and then 

 treated with liquor potassse, and examined microscopically, the 

 nodules will be seen to consist of large polyhedric refringent bodies, 

 held together by an amorphous substance acting as cement. 

 These bodies are the spores of the fungus causing the disease 

 (Trichosporum giganteum Behrend, 1890). The description of the 

 fungus is given on p. iioi. In Columbia it is generally believed 

 that the infection takes place by washing the hair with a mucila- 

 ginous oil, much used by the 'women of the country. In British 



