
Overview
This module describes how to give a shallow injection between the layers of the skin. Even though the technique is generic, this module will focus on Mantoux or Tuberculin Skin Testing (TST).
Indications
Contraindications
Patient information and consent
Always verify your patient’s identity and obtain informed consent before proceeding.
How do I explain this procedure?
“This is a TB test. I need to inject a little bit of a test substance just under the skin of the forearm.”
What can my patient expect?
“This will only sting for a moment. You will see a small blister where I injected it. Over the next three days it may grow or shrink, and it will start to fade away after that.”
What is my patient’s role?
“Do not rub or scratch the area. I am going to mark the injection area with a pen. Please do not wash the mark off. Let me know if you suddenly feel short of breath or get a rash after I injected this. Return to the hospital or clinic if you see an open wound on your forearm after a day or two. You need to return in two or three days so that we can read this test.”
Preparation

Documentation
Equipment
Site & Positioning
Use the left forearm and select a site 5-10 cm below the elbow joint, or roughly in the centre of the forearm. If the forearm cannot be used, the back of the shoulder may be used. Place the arm in extension. Ask a parent or assistant to restrain the child.
Procedure
Follow medical asepsis without gloves.
Troubleshooting
There is no wheal.
You may have injected too deeply, in the subcutaneous space. Try again on the same forearm, 5 cm away from your original site. Carefully aim more superficially.
Patient returns with skin ulceration at the site.
This is usually a strongly positive test. Prescribe a moderate potency corticosteroid cream.