Certified Medical Assistant (CMA AAMA)PharmacologyMedium

A medical assistant is preparing to administer an intradermal injection for a tuberculin skin test. Which of the following angles of insertion is appropriate?

  1. A15 degrees
  2. B25 degrees
  3. C90 degrees
  4. D45 degrees
Show answer & explanation

Correct answer: A. 15 degrees

Intradermal injections, such as for tuberculin skin tests, are administered at a 10-15 degree angle to ensure the medication enters the dermal layer just beneath the epidermis, creating a wheal.

Why the other options are wrong

  • B. 25 degrees is not a standard angle for any common injection route; it is too steep for intradermal and too shallow for subcutaneous.
  • C. 90 degrees is the appropriate angle for intramuscular injections.
  • D. 45 degrees is the appropriate angle for subcutaneous injections.

Intradermal Injection Angle

Intradermal injections are administered at a 10-15 degree angle to place medication into the dermis.

  • Used for allergy tests and TB skin tests.
  • Creates a small wheal or blister.
  • Shallowest injection depth.

Memory trick: ID is 'Low' at 15°, SubQ 'Mid' at 45°, IM 'High' at 90°.

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