Final answer:
Type IV (Delayed) hypersensitivity is the type of reaction expected in a client with itching two days after a tuberculin test, as it is a cellular-mediated immune response to prior exposure to Mycobacterium tuberculosis. The Correct Answer is Option .D.
Step-by-step explanation:
Among the types of hypersensitivity reactions, the one that is suspected in a client who reports itching two days after a tuberculin test is Type IV (Delayed) hypersensitivity. This response is a cell-mediated immune reaction involving sensitized T cells and macrophages that takes approximately one to two days post-secondary exposure to reach a maximal reaction.
It does not involve an immediate allergic reaction or autoantibodies, but rather a TH1 cytokine-mediated inflammatory response that can result in a localized reaction such as a rash or skin lesion. Typically, a positive tuberculin test showing a raised red area (induration) indicates previous exposure to Mycobacterium tuberculosis and a cellular immune response to the bacteria.