What is the test dose for PPD?

What is the test dose for PPD?

• A. 0.1 mL
• B. 0.5 mL
• C. 1 mL
• D. 10 mL

Answer: (A)

The amount used for a PPD test is kept very small to produce a controlled, localized reaction without causing systemic effects. The standard test dose is 0.1 mL, delivering 5 tuberculin units, injected intradermally to form a small wheal on the forearm. This precise dose is chosen so that people without TB exposure show little or no induration, while those with sensitization develop a measurable reaction that can be read 48–72 hours later. Larger volumes such as 0.5 mL, 1 mL, or 10 mL would not be appropriate for the Mantoux test and could lead to non-specific reactions or adverse effects.

The amount used for a PPD test is kept very small to produce a controlled, localized reaction without causing systemic effects. The standard test dose is 0.1 mL, delivering 5 tuberculin units, injected intradermally to form a small wheal on the forearm. This precise dose is chosen so that people without TB exposure show little or no induration, while those with sensitization develop a measurable reaction that can be read 48–72 hours later. Larger volumes such as 0.5 mL, 1 mL, or 10 mL would not be appropriate for the Mantoux test and could lead to non-specific reactions or adverse effects.