It has been said that "no synthetic drug has been introduced which has not in isolated cases given rise to symptoms of intolerance associated with cutaneous manifestations."1 The truth of this statement is being constantly confirmed by a steadily lengthening list of articles on the subject, with an increasing number of incriminated drugs. The status of the older remedies being pretty well established in this respect, present-day literature on the subject is largely concerned with the newer preparations, especially those of synthetic origin.
It would seem that two factors are especially involved in the production of such reactions, namely, the quantity of the drug and the reaction of the human organism to its presence. As to the procedure involved, there are two important possibilities, either a form of hypersensitivity or a toxic process. If the former is the mode of production, the quantity of the drug