Dracunculus medinensis (Dracontiasis).
The guinea worm develops in the dermis of human beings without any symptoms; only when it is completely grown does it form boil-like, extremely painful abscesses, in the greater majority of cases in the legs, in the region of the ankle, and is accompanied by general disturbance and a feeling of heaviness, dragging and pricking of the affected part; it occurs more rarely in the arms, certain parts of the back, the head, neck, scrotum and penis; in a superficial position the worm can occasionally be felt through the skin. In most cases there is only one worm and one abscess, but here and there one finds patients with three, four or even up to eight worms, and very exceptionally still more, as in the cases described by Poupée-Desportes[800] (fifty worms) and by Harington[801] (seventeen worms).
Diagnosis offers no difficulty when the worms are presenting or can be felt under the skin.
The inhabitants of the native home of the guinea worm, as a rule, quietly wait till it has got so far out that it can be conveniently grasped; it is then bound round with thread and fastened between the tips of a split piece of wood and slowly wound out. In ten to twelve days it can be wound out in this way. Emily[802] makes injections of a 1 in 1,000 solution of sublimate either in the neighbourhood of the worm or directly into its body. Mense[803] managed to remove the worm in one sitting by laying a wad of cotton wool soaked in chloroform on the exposed portion, thus stupefying it. Our therapeutic observations (Frangenheim[804]) favour the free laying open of the existing abscess and the consequent complete extraction of the worm.
Prophylaxis depends on care in the use of water in the guinea worm countries, especially dangerous being permanent waters infested by Cyclops sp.
Filaria bancrofti.
The parasitism of this filaria leads to the formation of lymphangitis, elephantiasis, chyluria, orchitis, chylocele, abscesses, lymphatic varices, perhaps also to chylous ascites and chylous diarrhœa.
Lymphangitis usually attacks the extremities, beginning generally with a rigor and swelling of the lymphatic vessels with adjoining lymph glands. The lymphatics become hard, knotty and extremely painful, the overlying skin red and swollen in longitudinal lines (Looss), high fever sets in with, to some extent, severe general disturbance. After some days the attack subsides, the swelling then partially disappears, but not completely, and often abscesses develop in consequence of the lymphangitis. Children, as a rule, suffer from such lymphangitic attacks (Finucane[805]).
Diagnosis is not easy, for many other causes frequently produce lymphangitis.