Final answer:
A patient with hives following contrast agent administration, which is a type I hypersensitivity reaction, may be given antihistamines or epinephrine, with epinephrine being crucial for severe reactions like anaphylactic shock. Desensitization therapy is a preventive treatment involving deliberate exposure to allergens over time.
Step-by-step explanation:
A patient who develops hives after administration of a radiologic contrast agent is likely experiencing a type I hypersensitivity reaction. In such cases, antihistamines or epinephrine may be administered to counteract the reaction. Antihistamines work to block the action of histamine, which is responsible for many of the symptoms associated with allergic reactions, such as hives. In more severe reactions, such as anaphylactic shock, epinephrine is the drug of choice as it works quickly to improve breathing, stimulate the heart, raise a dropping blood pressure, reverse hives, and reduce swelling of the face, lips, and throat.
Desensitization therapy is another long-term treatment strategy for hypersensitivity reactions, where dilute concentrations of allergens are injected over a period of time to reduce the severity of the allergic response.