Which patient is MOST likely to experience a delayed onset of allergic reaction?

A patient who ingests penicillin is most likely to experience a delayed onset of an allergic reaction due to the nature of certain drug allergies. When the body is exposed to a medication like penicillin for the first time, it may take time for the immune system to recognize it as a foreign substance and initiate an immune response. This response can lead to symptoms that appear hours to days after the initial exposure as the immune system primes itself and subsequently reacts to the medication.

In contrast, exposure to allergens such as latex, bee stings, or pollen tends to provoke more immediate allergic responses, primarily because these exposures involve pre-sensitized individuals. For example, a bee sting can trigger an immediate anaphylactic reaction, while latex or pollen can lead to quicker onset reactions in those with known sensitivities. Therefore, the delayed reaction associated with penicillin ingestion distinguishes it as the most likely scenario for such an allergic response.