OF THE various allergic conditions that allergists are called upon to treat, the best results are obtained in the management of seasonal hay fever.
In treating patients with seasonal hay fever by injections, the allergist does not completely desensitize. He simply makes the patient less sensitive to the noxious pollens to which he may be hypersensitive.
The mechanism by which this is accomplished depends upon the formation in the body of a blocking thermostabile antibody. It is produced by the repeated injections of pollen antigen. This blocking antibody should not be confused with the skin-sensitizing antibody, which is responsible for the production of symptoms when skin-sensitizing antibody combines with antigen and liberates histamine or "H"-substance. There are indications that another still unknown immunologic mechanism exists which is responsible for protection. This must be so, for there are patients who have no demonstrable blocking antibody and who, nevertheless, obtain relief from