What is the recommended volume for ID route?

• A. 0.5 mL
• B. 0.1 mL
• C. 0.2 mL
• D. 0.05 mL

Answer: (B)

Intradermal injections require a very small volume because only the superficial dermal layer should be occupied to form a visible bleb and ensure the antigen is presented properly without reaching deeper tissues. The standard amount used for ID administration is 0.1 mL. This small volume reliably creates a wheal and keeps the injection within the dermis, which is essential for tests like the tuberculin skin test or intradermal vaccines to yield accurate results. Using a larger amount would push the liquid into subcutaneous tissue or muscle, distorting the bleb and potentially altering the immune response. A volume like 0.05 mL might be too small to consistently produce a noticeable reaction, while 0.2 mL or 0.5 mL would be excessive for the dermal space and risks improper administration.