RINGWORM 479 



Clinical Examination 



The hairs should be treated first with ether and then with caustic 

 potash solution of about 7 per cent, strength. In this reagent they 

 may remain for from a few hours to a few days ; they are then 

 floated on to a slide and carefully covered with a cover-glass. 

 Permanent preparations may be mounted in Farrant's solution or 

 in glycerine jelly. 



Hairs, after treatment with ether, may be stained by the following 

 method : 



(1 ) Stain in anilin-gentian violet for one to two minutes, and blot, 



(2) Treat with Gram's iodine solution for one to two minutes, 

 and blot. 



(3) Decolorise carefully (watching microscopically) with anilin 

 oil containing 1 per cent, of hydrochloric acid. 



(4) Treat with anilin oil and then with anilin oil and xylol. 



(5) Clear in xylol, and mount in Canada balsam. 

 ERYTHRASMA. Due to infection with a fungus (Microsporon 



minutissimum), very difficult to cultivate, which occurs as extremely 

 long, fine filaments. 



FAVUS. Favus is due to a fungus discovered by Schoenlein in 

 1839 the Achiorion Schoenleinii. It is seen as a mycelial growth 

 with spores in the patches. The organism grows well on maltose 

 agar, forming fluffy, woolly, moss-like colonies with radiating out- 

 growths, first grey and then yellowish. It occurs on mice and other 

 animals. 



DHOBIE ITCH. Caste! lani has isolated three trichophyton-like 

 organisms in this disease. 



PITYRIASIS ALBA. In this disease Unna's " bottle bacillus " is 

 invariably present. It occurs as large round or oval bodies like 

 yeast-cells, which may occasionally show budding. 



PITYRIASIS VERSICOLOR. In the epidermal scales of this skin 

 affection a fungoid organism (Microsporon furfur) is present. It 

 occurs as short and thick curved hyphse between which are masses 

 of large coarse spores. It has not been cultivated (or very rarely). 



PINTA. A skin disease met with in South America. In the scales 

 short mycelial filaments with large (8-12 ^u) spores are seen. Various 

 organisms have been cultivated belonging to the genera PeniciHium 

 and Aspergillus. 



PIEDRA. A disease of the hairs met with in South America. 

 The nodosities on the hairs are composed of masses of very large 

 refractile spores. 



