From the beginning, the great bane of serum therapy has been serum sickness, the occurrence and severity of which can never be predicted. Individuals who do not give a history of previous sensitization often give reactions varying from death to an uncomfortable urticaria in certain diseases in which repeated doses of serum are given; and on the occurrence of successive infections, each of which call for serum treatment, the serum sickness is much more likely to occur and with greater severity.
Since the recognition of the fact that serum disease is a phenomenon of protein sensitization, or anaphylaxis, much research work has been done to find a means to prevent it, and as a result many suggestions have appeared in the literature, most of which have proved worthless or impracticable. On the basis of the fact that most anaphylactic phenomena are due to the contractions of plain muscle fibers, the