The intradermal TB skin test in an ape is performed at which site?

The intradermal TB skin test in an ape is performed at which site?

• A. Ear pinna
• B. Eyelid
• C. Forelimb
• D. Tail

Answer: (B)

The key idea is that an intradermal tuberculin test relies on a localized delayed-type hypersensitivity reaction that is easiest to read when the injection is placed in skin that is thin, hairless, and easy to visualize. In apes, the eyelid provides just that: very thin skin with good visibility of any induration or erythema, and it’s a site where tuberculin stays in the dermal layer long enough to produce a clear, measurable reaction. The eyelid is also practical for restrained animals and reduces interference from fur or movement that can complicate readings on other body sites. By contrast, areas like the ear pinna, forelimb, or tail often have thicker skin, more hair, or more motion, making the reaction harder to detect or read reliably. Hence, the eyelid is the preferred site for the intradermal TB skin test in apes.

The key idea is that an intradermal tuberculin test relies on a localized delayed-type hypersensitivity reaction that is easiest to read when the injection is placed in skin that is thin, hairless, and easy to visualize. In apes, the eyelid provides just that: very thin skin with good visibility of any induration or erythema, and it’s a site where tuberculin stays in the dermal layer long enough to produce a clear, measurable reaction. The eyelid is also practical for restrained animals and reduces interference from fur or movement that can complicate readings on other body sites. By contrast, areas like the ear pinna, forelimb, or tail often have thicker skin, more hair, or more motion, making the reaction harder to detect or read reliably. Hence, the eyelid is the preferred site for the intradermal TB skin test in apes.