Desensitization is a medical term which indicates a procedure that changes a person’s immune response to an allergen resulting in a temporary tolerance that lasts while the treatment is maintained. Despite typically maintaining the desensitization with large doses of the allergen, the initial phase of the desensitization procedure signals the immune system differently than when the body is simply overwhelmed by a large allergen exposure (which activates allergy cells). Instead, the desensitization process renders allergy cells temporarily inactive or in a regenerative state due to the particular signaling pattern used, and this state is maintained by continued constant exposure to a certain amount of the allergen.
Desensitization procedures are most commonly done to allow someone with a drug allergy to be able to take the medication safely if they really need it for treatment of a health condition. The process involves frequent doses of rapidly increasing amounts of the drug up until the desired dose (or a reaction occurs and the process is stopped) and then maintaining constant exposure to the drug at that desired dose to keep the allergy cells in the desensitized state until the patient’s medical treatment with the drug is completed. Once the desensitization treatment is complete, the patient’s allergic reactivity to the drug generally returns over short period of time, which is why this is called temporary tolerance.
These desensitization principles can be extrapolated beyond drug desensitization to be used for other types of allergies.