Page:Transactions of the Royal Society of Tropical Medicine and Hygiene, volume 1.djvu/300

272 Communicability.—Tinea cruris is known in the East as dhobie itch, from the popular belief that it is contracted from linen which has been contaminated while being washed by the dhobie. As to how far this belief is correct, I am not in a position to say. I have never succeeded in finding the fungus in clothes just received from the dhobie, either microscopically, or by inoculating small portions, of the linen itself in sugar media. I am, however, inclined to think that the popular belief may be to a certain extent correct, as a very few spores would be sufficient to set up the disease. I have been told by old sufferers, who had frequently been reinfected, that on their discontinuing to give their clothes to the dhobie, and having them washed in the house instead, the disease did not appear again. In Colombo dhobies are in the habit of washing the clothes in the lake or in small pools of water that are more or less stagnant; and it is certain that clothes belonging to infected persons are washed together with other clothes. Dhobie itch is very contagious : true epidemics occur in schools and among soldiers in barracks. I have several times observed that husbands infect their wives.

Diagnosis.—The diagnosis is easy in recent cases, the festooned appearance of the eruption limited by a sharp elevated bright red edge being quite typical In old cases, especially when secondary lesions, due to scratching are present, the diagnosis may be very difficult, the affection being often mistaken for eczema. A case sent to me had been previously treated as eczema for three months by Lassar's paste, calamine lotion, etc.

In doubtful cases, the microscopical examination will be of great help. It must, however, be noted that in old cases the fungus may be extremely scarce, the mycelium being practically absent, and only a few spores being found. It is well to take the scrapings for microscopical examination from the edge of the eruption.