What should be assumed about a patient's response to a subsequent exposure to the same antigen?

The assumption that a patient will react similarly to a subsequent exposure to the same antigen is grounded in the understanding of the immune response, particularly in the context of allergic reactions. Upon initial exposure to an antigen, the immune system may produce specific immunoglobulin E (IgE) antibodies, leading to sensitization. With subsequent exposures, the body's heightened immune response is more likely to occur, making it probable that the patient will have a similar reaction.

Medical desensitization, also known as immunotherapy, involves gradually exposing the patient to increasing doses of the allergen to build tolerance. Therefore, unless the patient undergoes such treatment, which can change the response over time, it is reasonable to expect that their reaction upon second exposure will mirror that of the first exposure.

This understanding of the immune system's behavior is vital for EMTs and provides essential context for managing allergic reactions in patients.