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TROPICAL DERMATOMYCOSES 



however, the condition is rare or absent in infants and children, 

 while the persons affected are generally young adults, but it may 

 be found also in very old persons. Women are attacked less fre- 

 quently than men. Villagers and people living in the country are 

 much more liable to contract the malady than people living in 

 large towns. It is doubtful whether there is any racial disposition. 

 In Fiji, however, it has been observed that while extremely common 

 in the indigenous population, it is comparatively rare among the 

 immigrant Indian coolies. The Tongans also are said to contract 

 the disease rarely, and this relative immunity, according to them, 

 is due to the habit they have of regularly anointing their bodies — 



Fig. 8i6. — ^Tinea Imbricata of the Forearm (Old Case). 



a habit not shared by the Fijians. A hot, moist, equable climate 

 seems to be the most suitable for the development of the fungus 

 and the spreading of the disease. Manson has justly remarked 

 that the climate which is suitable for the growth of cocoanuts is 

 also the best for the fungus of tinea imbricata. 



Symptomatology. — The eruption begins with one or several small, 

 roundish or oval, slightly raised, dark brownish patches, very itching. 

 Soon the central portion of each patch splits, and a ring of flaky large 

 scales attached at the periphery is formed. This scaly ring extends 

 peripherally, and in the meantime another brownish patch appears in 

 the centre at the site of the first brown spot ; the new brownish patch 

 breaks, and a second scaly ring is formed, which extends peri- 

 pherically inside the first ring, and so on until a very large roundish 

 patch is formed, containing several concentric scaly rings. Manson 

 has aptly compared this formation of rings fo concentric ripples 



