Syn.: Plerocercoides prolifer, Ijima, 1905; Sparganum prolifer, Verdun, Manson, 1907.
Fig. 215.—Sparganum prolifer: left with buds, right extended. × 4. (After Ijima.)
These plerocercoids produce an acne-like condition of the skin. The condition is really one of capsules in great abundance in the subcutaneous tissue and less so in the corium and in the intermuscular connective tissue. The encapsuled worms in the corium feel like embedded rice grains and raise the epidermis, giving rise to an acne-like condition. Many thousands occur scattered over the body; in Ijima’s Japanese case there were over 10,000 in the left thigh. The worms when they first appear in the skin cause itching. The capsules are ovoid, generally about 1 to 2 mm. in diameter, but they may be smaller and also much larger. The larger ones occur in the subcutaneous tissue. The capsules consist of dense tough connective tissue.
Each capsule, as a rule, contains one worm, but as many as seven may occur. The skin of areas that have been long infected is swollen and indurated or adherent, giving a somewhat elephantoid appearance. The subcutaneous tissue is thick and filled with slimy fluid or in other parts sclerosed.
Fig. 216.—Sparganum proliferum. × 10. (After Stiles.)
The Worm.—The chief peculiarity is its irregular shape and its reproduction in the larval stage by forming supernumerary heads, which are supposed to wander about the body.