Page:Transactions of the Royal Society of Tropical Medicine and Hygiene, volume 1.djvu/304

276 preparations from scrapings are almost always absent. The mycelium tubes are straight, occasionally showing a double contour; they are often dichotomous. Nieuwenhuis has grown the fungus, using Sabouraud's sugar media; the growth is very slow, the colonies are whitish and show a powdery surface.

The third tropical trichophytosis is the so-called

which was first described by Sabouraud in patients returning from Indo-China, Japan, and Tonkin. I have seen a few cases in Ceylon. The eruption generally commences on the uncovered parts of the body, ordinarily on the legs. The patients often state that they think the disease is due to prolonged immersion in stagnant water. The affection begins with erythematous patches, the surfaces of which are covered with minute pityriasis-like scales. Reaching, after a time, a diameter of one or one and a half inches, these patches become circinate. The circination, however, is incomplete; it is only segmentary. In dependent positions large polycyclic patches may be seen, but each forms only a half or a third of a circle, the rest of the arc being badly defined. The base of the patches, at this stage, is of a very dark bistre-brown colour. The border shows polymorphic lesions, mostly fine scales or minute vesicles and papules. The pruritis is very marked, and excoriations due to scratching are constantly present.

In chronic cases a thickening of the skin with lichenification takes place, especially at the circinate borders. The disease is difficult of cure in the Tropics, though it may disappear spontaneously on the patient proceeding to Europe. Chrysarobin ointment (1 to 4 per cent.) is the best treatment.

The Fungus.—Trichcophyton Sabouraudi (Castellani,