Observations on the specific exhaustion of cutaneous reactions

Cutaneous reactions in hypersensitive individuals are of two quite distinct types. The reactions observed in patients with hay fever or asthma and after sensitization by foreign serum develop in a few minutes, consist essentially of a wheal and erythema, and fade out completely in one to two hours. The skin then appears normal. There is no visible evidence of cell destruction. Such reactions may be obtained with extracts of pollen, animal dandruff and feathers, with food proteins, with foreign serum, and occasionally with bacterial or other proteins.

This type of cutaneous reaction has little in common with the local cutaneous reactions to tuberculin, typhoidin, luetin, and mallein. Here the reaction does not usually develop for 12 to 24 hours; it is characterized by induration and persistent signs of inflammation, requires many days to fade out entirely and clearly involves cell destruction. Zinsser 1 has recently shown that the local tuberculin reaction in the guinea-pig is independent of the development of a state of anaphylaxis and it is highly probable that the same holds true for the reactions of this type produced by other substances of bacterial origin.

Although it has commonly been assumed that the immediate skin reactions with urticaria-like lesions are manifestations of anaphylaxis, it has not been demonstrated that the mechanism consists of an antigen-antibody reaction. Similar reactions may sometimes be obtained with non-antigenic substances such as aspirin, salicylates and quinine, and there are a few substances, notably histamine, morphine and pituitrin, which produce this type of reaction in normal individuals. It appears to be essentially a vascular phenomenon with localized edema.

In an effort to determine the nature of these urticaria-like skin reactions we have studied their exhaustibility by a simple procedure in five hypersensitive patients, the subjects of hay fever or bronchial asthma.