THE FILIARIASES 279 



tion below the jufiction of the lacteals with the receptaculum chyli, but 

 when the fluid is milky the obstruction is beyond this point. 



Obstruction may be .caused by : — 



(i) A coiled-up mass of worms behind a valve or dilated sinus. 



(2) A single worm in a dilated lymphatic, the draining gland being 

 probably blocked by aborted ova. 



(3) Constant irritation caused by worms may lead to the permanent 

 blocking of a main lymph channel. 



There is often much fibrosis of the glands, when the lymphatics can 

 be seen collected in clusters between tissue strands. This condition 

 is accompanied by an excessive number of eosinophile cells in the 

 glandular substance (Bahr). 



The clinical manifestations are according to the site of the obstruc- 

 tion. This may be anterior or posterior to the junction of the lacteals 

 with the receptaculum chyli. 



(i) When the obstruction is anterior to the junction of the lacteals 

 with the receptaculum chyli there are chylous extravasations. The 

 thoracic duct may be blocked which results in the engorgement of the 

 lymphatics of the renal, lumbar and the pelvic regions with dilatation 

 of the lacteals. 



If the engorged vessels of the urinary tract rupture, chyluria results. 



If some blood vessels rupture also, as is common, then one has 

 hsemato-chyluria, the milky opacity being due to the large amount of 

 protein and not to fat. 



If the engorged vessels of the abdomen rupture, one has chylous 

 ascites. 



If the engorged vessels of the tunica vaginalis rupture, one has 

 chylooele. 



(2) When the obstruction is posterior to the junction of the lacteals 

 with the receptaculum chyli, one finds ordinary ascites, hydrocele lymph 

 scrotum and the varicose groin glands. 



The resistance of the tissues is lowered by this condition and inflam- 

 mation is readily set up which may go on to abscess and elephantiasis. 



The causes of Elephantiasis can be grouped as follows : — 



(i) As described above. 



(2) An injury to the female worm may cause abortion and conse- 

 quent obstruction of the lymphatics by the aborted eggs. The normal 

 microfilaria although 250 to 300 fx long is onlv 7 to 8 /x in breadth, v.hile 

 the aborted eggs are 50 by 34 /u, hence it can be readily understood that 

 eggs 34 X in their smallest diameter would completely block lymphatic 

 vessels along which microfilaria 7 to 8 yu. in diameter could travel. 



Lymph stasis causes inflammation and hypertrophy of the connective 

 tissue with excess of lymph and hence the limb enlarges (Manson). 



