ECZEMA 



2271 



of Sinhalese natives, apparently identical with acrodermatitis per- 

 stans of Hallopeau. They were different cHnically from the 

 acrodermatitis vesiculosa described by one of us. 



Psoriasis is considered by most writers to be extremely rare or 

 absent in native races in the tropics. Rutz states that he never 

 saw a single case of psoriasis in a negro during his many years of 

 practice in, Martinique. Howard Fox, senior, thinks that possibly 

 the savages of Africa are free from psoriasis on account of exposure 

 of the skin to sunlight, and that the negroes of North America 

 have inherited this pecu- 

 liarity. In our experi- 



ence, psoriasis is fre- 

 quently met with in the 

 tropics in Europeans and 

 natives of every race. 



Seborrhoeic affections 

 are common in the 

 tropics, especially in 

 /Europeans. A sebor- 

 rhceide of the chest is 

 frequently met with, and 

 often confused with ring- 

 worm. The microscop- 

 ical examination will 

 clear the diagnosis. The 

 use of a sulphur ointment 

 (5 per cent.) is the best 

 treatment. 



In Ceylon a peculiar 

 form of seborrhoea cap- 

 itis with yellowish scales 

 is occasionally seen in 

 European children be- 

 tween four and twelve 

 years of age. This affec- 

 tion is probably due to 

 Pityrosporum cantliei 

 Castellani, 1908, and 

 quickly disappears when 

 the child goes to cooler 

 climates. 



Dermatitis exfoliativa (pityriasis rubra) is not rarely met with, 

 occasionally following on psoriasis. In Ceylon we have observed 

 two cases in Sinhalese natives. The amount of desquamation w^as 

 enormous. On removing the scales, which were white, the skin 

 appeared of an angry red colour. At times, on superficial examina- 

 tion, certain cases may be mistaken for diffuse tinea imbricata. 



Fig. 896. — Dermatitis Exfoliativa simu- 

 lating Tinea: Imbeicata, 



