ANKYLOSTOMUM DERMATITIS
A form of dermatitis affecting the feet of coolies on plantations in Assam, in the West Indies, and probably elsewhere in the tropics, and variously known as ground itch, pani-ghao, water itch, water pox, water sores, sore feet of coolies, has been ascribed by Bentley to the penetration of the skin by anky lostomum larvæ. This disease is of much economic importance to the planter.
The soil in the neighbourhood of coolie lines is extensively contaminated by fæcal matter. During rainy weather the ankylostomum ova in the fæcal materials are hatched, and the larvae escape into, and possibly multiply in, the damp earth. The bare feet of the coolies are constantly soiled with this larva-laden earth, and in this way, in many tropical plantations, Looss's experiment is unintentionally carried out on a large scale. Dermatitis, vesiculation, and it may be pustulation or even extensive ulceration, and probably ankylostomiasis anæmia ensue. The services of the affected coolie are lost to the planter till the irritation or ulceration subsides and the anæmia is cured.
Bentley's suggestion has been contradicted by Dalgetty, Stiles, and others. Looss also points out that the symptoms of ground itch do not tally with those caused by the penetration of ankylostomum larvæ through the skin. Perhaps coolie itch may not in every instance be produced in this way, but undoubtedly it is so in a proportion of cases. A patient of mine, a sugar planter, who at that time knew nothing about the ankylostomum, observed that an attack of coolie itch in any of his labourers was sure to be followed by anæmia. He assumed that the skin trouble was the cause of the anæmia, and that the former was produced by a micro-organism picked up from the soil. He made his coolies, on going out to their work in the morning, walk through a bucket of Barbados tar, and then through a heap of sand, with the result that coolie itch and anæmia ceased on his estate.