The angle of insertion for an intradermal (ID) injection is:

Appeared in: RML MAINS 2025

Explanation

Intradermal (ID) injections are administered into the dermis, the layer of skin just below the epidermis.
This route requires a very shallow angle of 5 to 15 degrees to ensure the medication is not injected deeper into the subcutaneous tissue.
The primary goal is to create a small, visible bleb or wheal, which is characteristic of a correctly administered ID injection.
This technique is standard for sensitivity tests, such as tuberculin skin tests and allergy testing, where a local reaction is observed.

Option B: A 30-degree angle is not a standard angle for any of the common parenteral injection routes (ID, Sub-Q, IM). It is too steep for an ID injection and generally too shallow for a Sub-Q or IM injection.
Option C: A 45-degree angle is used for subcutaneous (Sub-Q) injections, not intradermal injections. This angle deposits medication into the fatty tissue below the dermis.
Option D: A 90-degree angle is used for intramuscular (IM) injections to deliver medication deep into a muscle. Using this angle for an ID injection would place the medication far too deep.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Parenteral Medication Administration: Injection Angles as background academic context rather than a clinical decision trigger.
Using the correct injection angle is a critical nursing skill that ensures medication efficacy and patient safety.
An incorrect angle can lead to the medication being absorbed at the wrong rate, causing either a delayed therapeutic effect or a potentially dangerous rapid absorption.
For diagnostic tests like the Mantoux test, an incorrect angle (e.g., injecting into subcutaneous tissue) will invalidate the result, requiring the patient to undergo re-testing.

How to Approach the Question

This is a factual recall question that tests your knowledge of fundamental nursing procedures.
First, identify the key terms in the question: 'intradermal (ID) injection' and 'angle of insertion'.
Recall the three main parenteral injection routes and their corresponding angles.
Mentally visualize or remember a chart of injection angles: Intradermal is the shallowest (almost parallel to the skin), Subcutaneous is next (45° or 90°), and Intramuscular is the deepest (90°).
Compare the recalled angle for ID injections (5-15 degrees) with the given options.
Select the option that falls within this established range.

Concept Tested & Keywords

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E6 Pharmacology Nursing Lilley 11e Part 1 p. 132-134

E6 Nursing Fundamentals Potter Perry 12e Part 3 p. 173-175

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