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Tuberculin Tests

Generic name: tuberculin purified protein derivative systemic

Brand names: Aplisol, Tubersol, Aplitest, Mono-Vacc Test (OT), Tuberculin Tine Test, Sclavo Test-PPD

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Solution, Intradermal:

Aplisol: 5 units/0.1 mL (1 mL, 5 mL) [latex free; contains phenol, polysorbate 80]

Tubersol: 5 units/0.1 mL (1 mL, 5 mL) [contains phenol, polysorbate 80]


Mechanism of Action

Tuberculosis results in individuals becoming sensitized to certain antigenic components of the M. tuberculosis organism. Culture extracts called tuberculins are contained in tuberculin skin test preparations. Upon intracutaneous injection of these culture extracts, a classic delayed (cellular) hypersensitivity reaction occurs. This reaction is characteristic of a delayed course (peak occurs >24 hours after injection, induration of the skin secondary to cell infiltration, and occasional vesiculation and necrosis). Delayed hypersensitivity reactions to tuberculin may indicate infection with a variety of nontuberculosis mycobacteria, or vaccination with the live attenuated mycobacterial strain of M. bovis vaccine, BCG, in addition to previous natural infection with M. tuberculosis.


Onset of Action

Delayed hypersensitivity reactions: 5-6 hours; Peak effect: 48-72 hours

Duration of Action

Reactions subside over a few days

Use: Labeled Indications

Tuberculosis skin test: An aid in the diagnosis of tuberculosis (TB) infection.


Hypersensitivity to tuberculin purified protein derivative (PPD) or any component of the formulation; previous severe reaction to tuberculin PPD skin test (TST); documented active TB or clear history of treatment for TB infection or disease; extensive burns or eczema.

Dosage and Administration

Dosing: Adult

Note: Dosing below is based on US/Canadian products which contain the PPD-S formulation; in regions outside of North America other products may be used, including the RT 23 formulation, and standard doses may differ between products as the units are not equivalent (Yang 2012).

Tuberculin skin test: Intradermal: 5 units (0.1 mL)

TST interpretation: Criteria for positive TST read at 48 to 72 hours (see Note below for health care workers; CDC 2000):

Induration ≥5 mm: Patients with HIV infection (or risk factors for HIV infection, but unknown status), recent close contact to person with known active TB, patients with chest x-ray consistent with prior TB, patients with organ transplants and other immunosuppressed patients (receiving the equivalent of prednisone ≥15 mg/day for ≥1 month

Induration ≥10 mm: Patients with clinical conditions that increase risk of TB infection, recent immigrants (ie, ≤5 years) from high-prevalence countries, IV drug users, residents and employees of high-risk congregate settings, mycobacteriology laboratory workers, children <4 years of age, or infants, children, and adolescents exposed to adults at high risk

Induration ≥15 mm: Patients who do not meet any of the above criteria (no risk factors for TB)

Note: A two-step test is recommended when testing will be performed at regular intervals (eg, for health care workers). If the first test is negative, a second TST should be administered 1 to 3 weeks after the first test was read.

TST interpretation (CDC guidelines) in a health care setting (CDC 2005):

Baseline test: ≥10 mm is positive (either first or second step); 0 to 9 mm is negative

Serial testing without known exposure: Increase of ≥10 mm is positive

Known exposure:

≥5 mm is positive in patients with baseline of 0 mm

≥10 mm is positive in patients with negative baseline or previous screening result of >0 mm

Dosing: Geriatric

Refer to adult dosing.

Dosing: Pediatric

Tuberculin skin test: Intradermal: Infants ≥6 months, Children, and Adolescents: Refer to adult dosing.


For intradermal administration only; do not administer IV, IM, or SubQ. Administer to upper third of forearm (palm up) ≥2 inches from elbow, wrist, or other injection site. If neither arm can be used, may administer to back of shoulder (CDC 2005). Avoid skin that is red or swollen; avoid visible veins. Administer using 1/4- to 1/2-inch 27-gauge needle or finer tuberculin syringe (CDC 2005). Should form wheal (6 to 10 mm in diameter) as liquid is injected which will remain ~10 minutes. Avoid pressure or bandage at injection site. Should wheal fail to form, repeat the test immediately at another site, at least 2 inches from the first site and circle the second injection site as an indication that this is the site to be read. Document date and time of injection, person placing TST, location of injection site, and lot number of solution. Read test at 48 to 72 hours following placement. Test results should be documented in millimeters even if classified as negative. Erythema and redness of skin are not indicative of a positive test result.


Store at 2°C to 8°C (36°F to 46°F); do not freeze. Protect from light. Opened vials should be discarded after 30 days.

Drug Interactions

Vaccines (Live): May diminish the diagnostic effect of Tuberculin Tests. Management: If a parenteral live vaccine has been recently administered, a scheduled PPD skin test should not be administered for at least 4-6 weeks following the administration of the vaccine. Exceptions: Cholera Vaccine. Consider therapy modification

Test Interactions

False-positive reactions may occur with BCG vaccination or previous mycobacteria (non-TB) infection (previous BCG vaccination is not a contraindication to testing; however, an interferon gamma release assay is preferred [CDC 2010]). False-negative reactions may occur with any condition that impairs or attenuates cell-mediated immunity, including aging.

Adverse Reactions

Frequency not defined:

Cardiovascular: Presyncope, syncope

Dermatologic: Erythematous rash, localized erythema, localized vesiculation, rash at injection site, skin rash, skin ulceration at injection site, urticaria at injection site

Hypersensitivity: Anaphylactoid reaction, anaphylaxis, angioedema, hypersensitivity reaction

Local: Injection site reactions, discomfort at injection site, hematoma at injection site, injection site scarring, local pruritus, localized edema, local tissue necrosis, pain at injection site

Respiratory: Dyspnea, stridor

Miscellaneous: Fever


Disease-related concerns:

  • Viral infections: Skin testing may be deferred with major viral infections.

Concurrent drug therapy issues:

  • Drug-drug interactions: Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information.

Special populations:

  • Pediatric: Infants <6 months of age may have an absent or delayed response.

Other warnings/precautions:

  • Administration: For intradermal administration only; do not administer IV, IM, or SubQ. Epinephrine (1 mg/mL) should be available to treat possible allergic reactions.
  • Appropriate use: Patients with a previous severe reaction to TST (vesiculation, ulceration, necrosis) at the injection site should not receive tuberculin PPD again.
  • Conditions decreasing response: Tuberculous or other bacterial infections, fungal infections, viral infection, live virus vaccination, malignancy, corticosteroids or immunosuppressive agents, chronic renal failure, severe protein depletion, afibrinogenemia, and other conditions that impair immune response may cause a decreased response to test.

Monitoring Parameters

Monitor for immediate hypersensitivity reactions for ~15 minutes following injection.


Pregnancy Risk Factor


Pregnancy Considerations

Animal reproduction studies have not been conducted. Pregnancy is not a contraindication to testing (CDC 2005).

Patient Education

What is this drug used for?

  • It is used during a TB (tuberculosis) test.

Other side effects of this drug: Talk with your doctor right away if you have any of these signs of:

  • Severe dizziness
  • Passing out
  • Injection site burning, discoloration, pain, skin breakdown, or swelling
  • Signs of a significant reaction like wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat.

Note: This is not a comprehensive list of all side effects. Talk to your doctor if you have questions.

Consumer Information Use and Disclaimer: This information should not be used to decide whether or not to take this medicine or any other medicine. Only the healthcare provider has the knowledge and training to decide which medicines are right for a specific patient. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this medicine. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not specific medical advice and does not replace information you receive from the healthcare provider. You must talk with the healthcare provider for complete information about the risks and benefits of using this medicine.

Source: Wolters Kluwer Health. Last updated January 29, 2020.