SYMPTOMS 293 



from the severity of the first symptoms. In some of the worst 

 cases the first symptoms are very mild. 



In nine or ten days or longer the second stage of the disease 

 appears, accompanying the period of migration of the larvae. 

 This is the period which is frequently fatal. The most pro- 

 nounced symptoms are intense muscular pains and rheumatic 

 aches, with disturbances in the particular muscles invaded, in- 

 terfering with the movements of the eyes, mastication, respira- 

 tion, etc., the respiratory troubles becoming particularly severe 

 in the fourth and fifth weeks of the disease, in fact sometimes 

 so severe as to cause death from dyspnea or asthma. Profuse 

 sweating and more or less constant fever, though sometimes 

 occurring in the first stage also, are particularly characteristic 

 of the second stage. The fever is commonly absent in children. 

 The third stage, accompanying the encystment of the parasites, 

 begins about six weeks after infection. The symptoms of the 

 second stage become exaggerated, and in addition the face again 

 becomes puffy, and the arms, legs and abdominal walls are also 

 swollen. The patient becomes very anemic, skin eruptions occur, 

 the muscular pains gradually subside and the swollen portions 

 of the skin often scale off. Pneumonia is a common compli- 

 cation in the third stage. 



Trichinella is unique among worms in causing constant fever. 

 It is probable that the fever as well as certain changes in the 

 blood corpuscles and chemical changes in the invaded muscles 

 is due both to poisonous substances given off by the worms and 

 to poisonous substances resulting from destroyed muscle tissue. 

 Such substances have been found by Flury and Groll and others 

 in cases of Trichinella infection. They are substances which 

 act on the muscles themselves, on the nervous system, and on the 

 bloodvessels. It is quite evident, as pointed out by Herrick, that 

 with the invasion of the blood and tissues by millions of larvae 

 and with the breaking down of large amounts of muscle tissue 

 a constant inoculation of the infected person with poisonous 

 protein material is taking place, a condition which always gives 

 rise to fever. Certain volatile acids are produced by the muscle 

 degeneration, and these are considered by Flury to account for 

 the muscular pains. Other toxic substances account for most of 

 the other symptoms of the disease, e.g., the marked increase in 

 certain kinds of white blood corpuscles, the eosinophiles. 



