ANAPHYLAXIS OR SERUM SICKNESS. 499 



was doubtless the paralysis of the lungs, owing to the poisoning 

 of the nerve centre in the medulla oblongata which controls 

 their action. 



G. 

 Anaphylaxis or Serum Shock. 



When anti-venomous serum is injected into a man for the 

 first time in small or large doses, it neutralizes the snake venom 

 m the blood, and is afterwards cast out of the body without 

 inducing any constitutional disturbance. However, if a second 

 dose is given months or years afterwards, serum shock or Ana- 

 phylaxis often occurs. Anti-venomous serum is made from the 

 blood of horses rendered highly immune to snake venom. Horse 

 serum of any kind, if used more than once, will produce serum 

 shock or serum sickness. Doctors now use specialized serum for 

 the treatment of certain diseases, such as diphtheria, plague, 

 lockjaw, chronic ulcers, etc. ; and to stop persistent bleeding after 

 an operation. 



If a person happens to be bitten by a venomous snake, and if 

 he has been injected with serum (not vaccine) at any previous 

 time in his life, anti-venomous serum should not be too hastily 

 administered. It must be borne in mind that non-venomous 

 snakes will readily bite if trodden on, or otherwise irritated. A 

 number of South African species of snakes are only venomous to 

 a slight degree. The fangs of these are set far back in the jaw, 

 and when they inflict a bite, as likely as not, the skin will only 

 be punctured by the soHd harmless teeth. Even when a typical 

 venomous snake bites, it by no means follows that it has inocu- 

 lated its victim with a fatal dose of venom. In many instances 

 the quantity of venom injected is so small that recovery occurs 

 without any treatment. If the symptoms do not warrant an 

 immediate full injection of serum, then ten drops of the serum 

 should be injected at once to lessen the subsequent danger from 

 serum shock when a fuU dose is subsequently given. The 

 patient should be watched, and if sure signs of snake venom 

 poisoning are developing, then inject 10 c.c. of serum. If 

 this proves sufficient to arrest the developing symptoms of 

 poisoning, then do not give any more. If, however, the patient 

 is getting worse, inject a second bottle of 10 c.c, and even 

 more if the case is a very serious one, especially so if treat- 

 ment has been long delayed, or the bite is from any species 



