442 Diphtheria 



in which local and metastatic abscesses have been observed, 

 the condition is probably correctly attributable to infection 

 from the patient's skin or from the syringe. 



I have found that the serums are by no means regular 

 in the rapidity of deterioration, so that no very old serum 

 should be used. 



Freezing is without effect upon the serum and ordinary 

 temperature-changes are harmless to it. The antitoxic 

 power is destroyed at 60 C., the point at which the serum 

 coagulates. The antitoxin is precipitated with the globu- 

 lins.* 



The serums from different horses probably vary much 

 in both their irritant and globulicidal properties, so that 

 mixed serums from a number of horses may be preferable to 

 that from a single horse. 



Prophylaxis. The serum can be relied upon for prophy- 

 laxis in cases of exposure to diphtheria infection. In most 

 cases a single dose of 500 units is sufficient for the purpose. 

 The transitory nature of the immunity afforded by prophy- 

 lactic injections of antitoxin is probably dependent upon the 

 fact that the antitoxin is slowly excreted through the kid- 

 neys. 



Treatment. For treatment no dose smaller than 1000 

 units should be given and in older children and adults the 

 dose should be 2000 units. The administration of the 

 remedy should be repeated in twelve hours if the disease 

 is one or two days old, in six hours'if three or four days old, 

 in four hours if still older. The serum may have to be given 

 two, three, four, or even more times, according to the case. 



Diphtheria antitoxin is always to be administered by the 

 hypodermic method, wherever the skin is loose. Some clini- 

 cians prefer to inject into the abdominal wall, some into 

 the tissues of the back. A slightly painful swelling is 

 formed, which usually disappears in a short time. Occa- 

 sionally there is an immediate outbreak of local urticaria 

 rarely general urticaria. Sometimes considerable local 

 erythema results. The occasional reports of successful 

 oral administration are very doubtful observations. Se- 

 rums of high unit strength can be given with the ordi- 

 nary hypodermic syringe; those of lower strength, of 

 which a larger quantity is required, must be given with 



*See paper by J. P. Atkinson, "Journal of Experimental Medicine," 

 Sept. and Nov., "1899, vol. iv, Nos. 5 and 6. 



