What must be documented for intradermal injection?

Record product, lot, dose, route, site, wheal presence at placement, time, administrator, reading appointment, and at the reading visit the induration measurement in millimetres and clinical interpretation pathway.

Intradermal Injection: Nursing Procedure Steps & Safety Guide | NurseOnShift

🧫 Skin testing & ID route

Intradermal Injection: Wheal Technique, TB Skin Tests & Allergy Testing

A shallow-dermis guide for nurses placing intradermal (ID) injections—from medication administration and hand hygiene through wheal verification, the 48–72 hour tuberculosis reading window, and immediate monitoring after allergy skin testing.

12 min read

Updated 23 May 2026

Medically Reviewed

Written by

Sid A. Abdala Balal

RN — Registered Nurse

Medically Reviewed by

Dr. Adam Sayedi

MD — Medical Doctor

Quick facts

Insertion angle

Shallow (often 5–15°)

Success cue

Visible wheal / bleb

TST read window

48–72 h post-placement

Primary harms

Invalid test, false results, allergy

Key takeaway

Intradermal work succeeds when the dose sits in the dermis, not subcutaneous fat or muscle: verify a pale wheal after placement, schedule 48–72 hour reading for tuberculin skin tests, and treat a missing wheal or wrong depth as an invalid test that must be repeated on a new site—not charted as complete.

Quick procedure summary

Item	Detail
Procedure	Injection administration (intradermal)
Also known as	ID injection, Mantoux technique, TB skin test injection, allergy testing injection
Category	Medication administration
Purpose	Deposit a small volume into the dermis to elicit a local immune response (e.g., tuberculin skin test) or deliver agent for allergy testing
Who performs	Registered nurses and other designated, trained clinicians per scope and local authorisation
Typical settings	Employee health, primary care, school health, allergy clinics, pre-admission screening, public health programmes

Overview

Intradermal injection delivers a small volume into the dermis—the layer between epidermis and subcutaneous tissue. Nurses most often encounter it for the tuberculin skin test (TST / Mantoux), which uses purified protein derivative (PPD) to detect latent tuberculosis infection, and for allergy skin testing where wheal-and-flare responses guide interpretation.

Unlike subcutaneous or intramuscular routes, the clinical endpoint is often a visible wheal and a timed reading—not immediate systemic effect. Technique errors (too deep, wrong volume, no bleb) invalidate TST results and can delay occupational or pre-operative screening.

Two-part workflow

Placement and reading may be done by different trained providers. Your organisation should define who may place, who may read, and how missed 72-hour returns are rescheduled—consult state or local public health guidance where applicable.

Indications

Indication category	Nursing rationale
Latent TB infection screening	TST placement when blood-based Quantiferon TB Gold testing is unavailable or not selected per protocol.
Baseline occupational health testing	Healthcare and congregate-setting personnel may require two-step baseline testing before periodic retesting—follow institutional policy.
Allergy skin testing	Intradermal dilutions after negative prick tests for selected allergens; immediate observation for systemic anaphylaxis symptoms.
Other ID-ordered agents	Some local anaesthetics or product-specific tests use ID technique—always follow manufacturer information for use and pharmacy guidance.

Contraindications and when to pause

For TST, CDC guidance notes contraindication primarily after a severe prior TST reaction (e.g., necrosis, blistering, anaphylactic shock, ulcerations). Most other groups, including infants and people with HIV, are not contraindicated—but timing with live-virus vaccines and prior positive TB tests matters.

Do not place TST when

Documented prior positive TB blood or skin test without a new clinical indication.
History of severe reaction to previous TST unless specialist plan exists.
Active TB treatment pathway already underway—coordinate with the TB programme.

Defer or reschedule when

Recent live-virus vaccination (measles, MMR, varicella, etc.)—TST ideally same day or ≥4 weeks later per CDC timing guidance; institutional protocols may vary.
Extensive rash, burns, or eczema at all forearm sites—seek alternate site or prescriber input.
Patient cannot return for 48–72 h reading—reschedule rather than placing a test that will expire unread.

Escalate early if

Systemic allergic signs during allergy ID testing—prepare epinephrine per protocol.
Large painful induration, blistering, or lymphangitis after placement.
Symptoms suggestive of active TB disease—do not wait for TST reading before further work-up.

Equipment

For Mantoux TST, CDC specifies a tuberculin syringe with a short 27-gauge needle and 0.1 ml PPD solution—verify product and cold-chain storage per pharmacy policy.

✓Tuberculin or allergy-test solution per order (check expiry and storage)

✓1 ml tuberculin syringe with 26–27 G short needle (product-specific)

✓Alcohol swab or skin antiseptic per policy

✓Gloves when exposure to blood or body fluids is anticipated

✓Ruler or millimetre grid for induration measurement at reading visit

✓Sharps container at point of care

✓Appointment slip or electronic reminder for 48–72 h reading

✓Allergy emergency kit when performing intradermal allergy tests

Volume and needle

Incorrect dose or depth invalidates TST. Use a fresh sterile needle and syringe for each patient; never reuse between patients. Multi-dose vial access follows your facility’s injection-safety and medication policies.

Pre-injection checks

✓Two identifiers; confirm order, indication, and prior TB test history

✓Review allergies, BCG history, immunosuppression, and recent vaccinations

✓Inspect volar forearm (or protocol site) for scars, venepuncture bruises, or active dermatitis

✓Confirm patient can return for reading within 48–72 hours—or defer placement

✓For allergy testing: baseline vital signs if policy requires; resuscitation equipment available

✓Explain wheal formation, reading appointment, and activity restrictions (avoid scratching site)

ID vs SC vs IM: depth at the bedside

Route confusion causes absorbed medication in the wrong plane and invalid skin tests. If the order says intradermal, do not use SC or IM technique.

Intradermal (ID)

Dermis — shallow angle, visible wheal

Small volumes (TST typically 0.1 ml per CDC)
Bevel up, ~5–15°; needle tip just under epidermis
Success = pale wheal; TST read at 48–72 h

Subcutaneous (SC)

Adipose — no wheal required

Insulin, heparins, many biologics
Often 90° or angled with skin fold
No delayed induration reading like TST

IM injections target muscle for different absorption kinetics—see IM injection when the order is not intradermal.

Wheal verification and invalid placement

CDC states that when placed correctly, TST should produce a pale elevation (wheal) 6–10 mm in diameter. If the wheal is absent, the dose is wrong, or injection is too deep, the test is invalid.

Invalid test actions

Report the incident per facility policy.
Repeat on a new site at least 2 inches (5 cm) from the failed attempt when protocol allows.
Do not document a completed TST if the wheal criteria were not met.

Observation immediately after ID dose	Likely meaning	Action
Pale wheal 6–10 mm (TST)	Correct intradermal plane	Mark site lightly if policy directs; schedule 48–72 h read; teach not to cover with occlusive dressing.
No wheal / blood at needle hub	Too deep or subcutaneous	Invalid—repeat per policy on new site.
Large wheal with urticaria and systemic symptoms	Allergic reaction during allergy testing	Stop testing; emergency pathway; document and treat per protocol.

Procedure steps (Mantoux TST focus)

Preparation

Perform hand hygiene and gather supplies

Bring tuberculin syringe, PPD vial per pharmacy release, alcohol swab, sharps container, and reading appointment materials to a well-lit area.

Verify identity, indication, and contraindications

Confirm no prior positive TB test documentation; review vaccination timing and skin integrity at planned site.

Draw up 0.1 ml tuberculin

Use tuberculin syringe graduated in 0.01 ml increments; expel air carefully without wasting dose; verify concentration per product label.

Implementation

Position forearm and cleanse skin

Place volar surface palm-up on a firm support; select an area 2–4 inches below the antecubital fossa free of scars; cleanse and allow to dry if policy requires.

Stretch skin and insert bevel-up

With nondominant hand, stretch skin taut. Insert needle slowly at shallow angle (about 5–15°) with bevel facing up until bevel is just visible beneath the skin surface.

Inject slowly and form wheal

Depress plunger smoothly to deliver full 0.1 ml; a pale wheal should appear. Do not aspirate for standard TST technique.

Sterility checkpoint

Confirm wheal diameter and that the needle did not re-enter the vial after patient contact. Engage sharps safety immediately—do not recap.

Completion

Withdraw, discard sharps, and mark site if directed

Withdraw at same angle; dispose needle/syringe in sharps bin; light ink-free mark or patient instruction card may help the reader locate the site.

Schedule reading and educate

Book 48–72 hour return; explain that induration—not redness alone—will be measured; instruct to avoid scratching and heavy occlusion at site.

Document placement

Record product, lot, site, wheal presence, time, administrator, and reading appointment in the health record.

Reading window: induration, not erythema

CDC guidance: read TST between 48 and 72 hours after placement. Measure the induration (firm swelling) in millimetres perpendicular to the long axis of the forearm—not erythema alone. Patients who miss the window need rescheduling; repeated placement can cause boosting in some persons.

Positive millimetre cut-offs depend on TB risk category (5 mm, 10 mm, or 15 mm thresholds per CDC)—interpretation is a clinical/public-health decision, not a nursing-only call in isolation.

After a positive read

Positive results trigger further evaluation—often including chest X-ray and clinical assessment per TB programme pathways. Report active or latent TB per local requirements.

Two-step TB baseline screening

Some employee-health programmes use two-step testing for initial baseline to detect boosted reactions in persons infected long ago. If the first TST is negative, a second test is placed 1–3 weeks later per CDC occupational guidance; a positive second test may represent boosted immunity rather than new conversion.

Coordinate with occupational health so nurses do not mislabel a boosted second test as a fresh exposure without clinical correlation.

Monitoring and complications

Finding	Concern	Nursing action
Local blistering or necrosis at TST site	Severe hypersensitivity	Document; notify clinician/TB programme; avoid repeat TST without specialist plan.
Wheal absent at placement	Invalid technique	Repeat on new site per policy; incident report if required.
Urticaria + hypotension during allergy ID test	Anaphylaxis	Emergency response; discontinue further allergens; treat per protocol.
Patient returns after 72 h	Unreadable TST	Reschedule new placement; educate on timing importance.
Swelling of regional lymph nodes with fever	Possible infection or adverse reaction	Clinical review; TB programme notification if related to TST.

Documentation

Placement note example

“TST (PPD) 0.1 ml intradermal left volar forearm 0900 by [name]; pale wheal 8 mm noted; patient booked TB read 0700 day after tomorrow; educated on 48–72 h window and no scratching.”

Minimum data set

Product, lot, dose, route ID, time, administrator
Site (left/right forearm) and wheal presence/size at placement
Reading appointment and who will read
At reading visit: induration mm, erythema noted separately, interpreter of result
Adverse events and TB programme notifications

Patient education

✓Return in 48–72 hours is mandatory for TST—missing the window invalidates the test

✓Expect mild itching or redness; avoid scratching, heavy bandages, and topical steroids on the test site unless directed

✓A positive TST does not mean active disease—it means further evaluation is needed

✓For allergy testing: remain in clinic for observation and report breathing difficulty or facial swelling immediately

Clinical pearls

Stretch the skin taut before insertion—loose skin invites subcutaneous deposition.
If you see a drop of blood but no wheal, assume invalid and repeat rather than hoping the read will suffice.
BCG history complicates interpretation but is not a contraindication to placement—risk-based follow-up still applies.
Allergy intradermal tests need resuscitation readiness; TST rarely causes anaphylaxis but severe local reactions occur—document objectively.

NCLEX practice questions

NCLEX-style clinical judgment practice — A wheal that spreads or blanches wrong can hide anaphylaxis—rehearse site selection, angle, and observation timing for intradermal injection, including a priority action, select-all-that-apply cue recognition, trend interpretation after intervention, and matrix escalation matching (recognise cues → analyse → prioritise → act → evaluate outcomes).

Unfolding case — employee health clinic. Ms. Rivera, 28, a new healthcare assistant, needs baseline TB screening before ward placement. She had BCG as an infant, denies TB symptoms, and can return Friday for a read (placement is Wednesday morning). Supplies: PPD vial from pharmacy, tuberculin syringe with 27 G needle, and Mantoux training checklist per policy.

Question 1 — Priority action

Which action should the nurse initiate first to reduce patient risk?

Apply gentle pressure until bleeding stops, document the placement as complete, and schedule the standard 48–72 h read on the same forearm site. Re-insert at the same puncture track using a steeper angle so tuberculin enters the dermis. Treat the placement as invalid per protocol, report if required, and repeat on a new site at least 2 inches away when authorised—not chart a completed TST. Hold pressure for two minutes, cover with a dry dressing, and proceed with the routine reading appointment without reattempting placement.

Question 2 — Select all that apply

Select all that apply — which factors should the nurse recognise before placing a TST?

Prior documented positive TB blood or skin test without a new indication to repeat Patient can return for reading 48–72 hours after placement Non-dominant forearm chosen for comfort without assessing skin integrity or prior test documentation Recent live-virus vaccination may require timing adjustment per CDC guidance Active dermatitis or scarring at all available forearm sites

Question 3 — Trend interpretation

Valid TST placed Monday 0800; patient returns Wednesday 0900 (within 48–72 h window) for reading:

Trend snapshot
Induration: 12 mm palpable firm swelling perpendicular to forearm axis
Erythema: 18 mm pink area surrounding site
Symptoms: denies cough, fever, night sweats, or weight loss
Vitals: afebrile; SpO₂ 98% on room air
Plan: occupational health algorithm pending read documentation

Select all that apply — which nursing actions are appropriate now?

Measure and document induration in millimetres—not erythema alone—and record reader, time, and site Chart the reaction as 18 mm using the larger erythema border because it is easier to see at the bedside Evaluate outcomes by comparing induration size to risk-based positive thresholds and triggering TB programme follow-up per protocol Document the read as negative because BCG history automatically invalidates any measurable induration Escalate for clinical TB evaluation if symptomatic disease is suspected regardless of mm read

Question 4 — Matrix judgment

For each situation during or after intradermal placement, select the best nursing action category (one per row).

Situation	Continue routine monitoring / supportive care	Notify clinician / urgent same-day pathway	Activate rapid response / emergency escalation
Valid 8 mm wheal at placement; patient educated; Friday read appointment confirmed
Patient returns 96 hours after placement requesting a read
Allergy intradermal test: new urticaria, wheeze, and BP 86/52 within 5 minutes
Mild itching at TST site; no induration yet at 24 h; afebrile

On a small screen, swipe or scroll sideways to see the full table.

Answer key & rationale

Next step Timed NCLEX Next Gen–style scenarios on NurseOnShift

Frequently asked questions

FAQ

What angle is used for intradermal injection?

For tuberculin skin tests, insert at a shallow angle—often about 5–15 degrees with the bevel up—so the solution forms a wheal in the dermis. Exact technique should match your training materials and CDC Mantoux guidance.

How soon must a TB skin test be read?

CDC recommends reading between 48 and 72 hours after placement. Results read outside that window are not reliable; the test usually needs to be repeated.

Should nurses aspirate before intradermal injection?

Standard Mantoux TST technique does not include aspiration. Allergy intradermal protocols may differ—follow the specific test kit and institutional policy.

What if no wheal forms after injection?

An absent wheal or incorrect volume typically invalidates the test. Report per policy and repeat on a new site at least 2 inches from the first attempt when allowed.

Can intradermal injections cause anaphylaxis?

TST anaphylaxis is rare; allergy intradermal testing carries higher systemic risk. Observe per protocol and escalate immediately for airway or circulation changes.

Is BCG vaccination a contraindication to TST?

No—but BCG can cause false-positive TST reactions. Interpret results using risk stratification; blood-based IGRA tests may be preferred in BCG-vaccinated persons per CDC guidance.

References

Centers for Disease Control and Prevention. Clinical testing guidance for tuberculosis: tuberculin skin test.
https://www.cdc.gov/tb/hcp/testing-diagnosis/tuberculin-skin-test.html
Centers for Disease Control and Prevention. Mantoux tuberculin skin test toolkit.
https://www.cdc.gov/tb/hcp/mantoux/index.html
Centers for Disease Control and Prevention. Safe injection practices and your health.
https://www.cdc.gov/injection-safety/index.html
Centers for Disease Control and Prevention. Core infection prevention and control practices for safe healthcare delivery.
https://www.cdc.gov/infection-control/hcp/core-practices/index.html
Royal Marsden Manual of Clinical Nursing Procedures — Procedures (RMM Online).
https://www.rmmonline.co.uk/contents/procedures
World Health Organization. Tuberculosis (health topic).
https://www.who.int/health-topics/tuberculosis

Editorial standards & medical review

About the author: Sid A. Abdala Balal, RN, writes evidence-based nursing education focused on practical bedside skills, patient safety, and clinical decision support for nurses.

Medical review: This guide is reviewed by Dr. Adam Sayedi, MD, for clinical accuracy, clarity, and alignment with current nursing standards for intradermal injection and tuberculin skin test placement.

Policies: Medical Review Process · Editorial Policy · Correction Policy