A TB test is administered by which route?

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Multiple Choice

A TB test is administered by which route?

TB screening is given intradermally, placing the purified protein derivative into the dermal layer just under the skin. This shallow placement lets skin-resident immune cells, like Langerhans cells, interact with the antigen and produce a localized delayed-type hypersensitivity reaction that you read as induration 48 to 72 hours later. If the antigen is injected into subcutaneous tissue, muscle, delivered intravenously, or taken by mouth, the immune response in the skin won’t develop in the same localized way, leading to inaccurate results. The goal is to create a small, raised wheal in the skin from proper intradermal placement, which is why this route is used rather than the others.

TB screening is given intradermally, placing the purified protein derivative into the dermal layer just under the skin. This shallow placement lets skin-resident immune cells, like Langerhans cells, interact with the antigen and produce a localized delayed-type hypersensitivity reaction that you read as induration 48 to 72 hours later. If the antigen is injected into subcutaneous tissue, muscle, delivered intravenously, or taken by mouth, the immune response in the skin won’t develop in the same localized way, leading to inaccurate results. The goal is to create a small, raised wheal in the skin from proper intradermal placement, which is why this route is used rather than the others.

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