(dē‵sen‵sĭt-ĭ-zā'shŏn )

[de- + sensitization]

1. Treatment of an allergy by repeated injections of a dilute solution containing the chemical mediators of inflammation. Gradually increasing concentrations of the antigen are used. The concentration is too weak to cause symptoms but strong enough to promote gradual immune tolerance. It increases the levels of immunoglobulin G, which blocks immunoglobulin E from binding to mast cells and initiating the release of the chemical mediators of inflammation. Although not always successful, desensitization is still commonly used, esp. for patients whose allergic response to an antigen is systemic anaphylaxis. SYN: antianaphylaxis; hyposensitization.

   SEE: allergy; anaphylaxis; tolerance.

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   The patient must be closely monitored for signs of anaphylaxis for at least 20 min after each injection of dilute antigen. Emergency drug therapy is maintained nearby for immediate treatment of anaphylaxis. Prescribed antihistamine therapy is provided to relieve lesser allergic symptoms, e.g., urticaria, pruritus, wheezing.

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2. In psychiatry, the alleviation of an emotionally upsetting life situation.

phobic d.Systematic desensitization.

systematic d.A form of behavior therapy, used particularly for phobias, in which the patient is gradually exposed to anxiety-producing stimuli until they no longer produce anxiety. SYN: phobic desensitization.

SEE: implosion flooding.