TINEA IMBRICATA [TOKELAU) 



2065 



have a cold and cool season — such as many parts of India and China 

 — the disease apparently does not spread. 



etiology. — The aetiology of this dermatomycosis has been the 

 subject of numerous controversies. Manson first, in 1872, de- 

 scribed a trichophyt on-like organism in the squamae; with the 

 laboratory technique of that time attempts at cultivation did not 

 succeed. Blanchard considered it non-cultivable, and called it 

 Trichophyton concentricum ' ; on the other hand, Nieuwenhuis 

 stated that it was quite easily cultivated direct on solid media from 

 the squamae, and was characterized by the colonies being craterif orm. 

 His results were not confirmed. In recent years the general opinion 

 has been that aspergillus-Hke fungi were the real cause of the disease. 

 Tribondeau described fructifications somewhat similar to those of an 

 aspergillus, and created for the fungus the genus Lepidophyton 



Fig. 815. — Tinea Imbricata. 



(A67rfcs=:scale; <^vtoi/= plant). Wehmer has described it as a true 

 aspergillus — Aspergillus tokelau. The investigations carried out 

 by Castellani have demonstrated that the aspergillus and aspergillus- 

 like fungi have nothing to do with the disease. When they are 

 present in the squamae, they are merely saprophytes or contamina- 

 tions. By using a special technique he has succeeded in growing 

 the true fungi causing the disease, which must be placed in the genus 

 Endodermophyton. Castellani recognized at first two species, and 

 later four: Endodermophyton indicum, Endodermophyton tropicale, 

 Endodermophyton concentricum, d^nd. Endodermophyton mansoni. It 

 is probable that further investigation wiU reveal the existence of some 

 more species. The description of these fungi will be found in 

 Chapter XXXVIII., p. 1016. 



Predisposing Causes. — As regards age, many authorities state that 

 the disease is more common in children than in adults. In Ceylon, 



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