The disease is endemic in certain localities in India China, Egypt, Arabia, the islands of the Pacific, etc., chiefly in places within a short distance of the sea. It obviously depends on some morbid poison, but the nature of it has not been discovered. The disease begins in an acute inflammation of the skin, accompanied by fever, and somewhat resembling erysipelas. These attacks pass off and recur, the disease ultimately subsiding into a more chronic condition. These are conditions which can only be produced by a morbid poison acting on the tissues locally and probably sending off products into the blood so as to induce fever. The fact that no secondary lesions occur at a distance is an indication that the virus itself does not reach the blood. The disease attacks chiefly the native races, but no race is exempt from it.
The lesion consists of'an enormous hypertrophy of the tissues of the skin. The cutis vera is thickened, the papillae are enlarged, and the epidermis is thickened. In the earlier periods the new-formed tissue is some what cellular, and throughout it is succulent and (edematous.
Fig. 136. - Elephantiasis affecting scrotum, legs and arms. (After photograph by Turner).
Fig. 137. - Hyperostosis and synostosis of the bones of the leg and foot in elephantiasis. The bones present everywhere flat or pointed projections. At + + + the tibia and fibula are united, as they are also above the ankle-joint. The astragalus and os calcis are also united. (Virchow).
The disease occurs chiefly in the lower extremities and external genital organs, but sometimes attacks the upper extremities. In the lower extremities it produces an extraordinary irregular thickening of the skin, which has a folded and bagged appearance, like that of the legs of an elephant. (See Fig. 136.) In the genital organs it produces tumours which sometimes grow to a massive size; tumours have been excised which weighed over 100 pounds, and which hung down so as to reach below the knees. (See Fig. 136.) Sometimes the tumour is not entirely made up of hyper-trophied skin, but a proper isolated tumour is found internally. This was so in a case observed by the author. In the legs the new-formation may extend inwards to the fasciae, the inter-muscular tissue, periosteum, and bone. The accompanying Fig. 137 shows how the bone may be the seat of new-formation.
Sometimes there is great dilatation of the lymphatic vessels. It is asserted that the disease may develop from so-called lymph-scrotum, and Manson has inferred that elephantiasis, like lymph-scrotum, depends on the filaria sanguinis. (See under Parasites.) The author does not regard this inference as warranted.
Virchow, Geschwiilste, vol. i.; Esmakch und Kulenkampff, Die elephantiastischen Formen, 1885; Carter, On Leprosy and Elephantiasis, 1874; Turner, Amputation of scrotum for Elephantiasis, Glas. Med. Jour., 1882, vol. i. (with photographs).