324 ILLINOIS STATE ACADEMY OF SCIENCE 



consist of a skin eruption, edema, slight albuminuria, en- 

 largement of the lymph nodes with pain and tenderness 

 and pain in the joints. The eruption is variable in char- 

 acter, a local eruption usually appearing earlier than the 

 general eruption. On the second or later injections the 

 period of incubation may be absent or shortened (immed- 

 iate or accelerated reaction). This does not, however, 

 always occur. This condition is not considered serious 

 and in many instances gives no greater discomfort than 

 that of an itching rash. Some samples of antitoxic or 

 other sera quite uniformly cause a skin eruption. The 

 earlier rashes are usually scarlatinaform, while those oc- 

 curring later are more frequently of an urticarial nature. 

 Von Pirquet and Schick believe that this reaction is due 

 to antigen-antibody combination, owing to the fact that 

 the average incubation period coincides with the time 

 of first appearance of precipitins in experimental ani- 

 mals. It is known, however, that precipitins may be 

 present without any manifestations of allergy whatever. 



Local Reactions. — The primary injection of antitoxic 

 or other sera may lead to local necrosis. When repeated 

 injections are given, a final subcutaneous injection will 

 more frequently result in a sharp local reaction, which 

 may terminate in necrosis. This may also occur with 

 rabies vaccine as well as with serum and is thought to 

 constitute a striking parallel to the so called Arthus 

 phenomenon in rabbits. It has been shown that such 

 necrosis is not due to bacterial contamination, but the 

 necrotic area may become infected and serious or even 

 fatal consequences follow. 



In connection with these serum reactions, there are 

 certain preventive measures which should be mentioned 

 briefly: 



(1) Desensitization to Serum. — It is a well known 

 fact that different lots of antitoxic or bactericidal sera 

 will vary widely in their rash and temperature-produc- 

 ing qualities. This may have a bearing on the develop- 

 ment or non-development of untoward symptoms. The 

 administration of small doses of serum prior to the first 

 injection or previous to subsequent injections of those 

 known to be sensitive to the same is frequently resorted 



