Tuberculin Purifed Protein Derivative (PPD)

How does it work?

Tuberculin purified protein derivative (PPD) is an extract of Mycobacterium tuberculosis, the bacteria that cause tuberculosis in humans. It is used to test if a person has been exposed to tuberculin protein, either from a previous tuberculosis vaccination, or from environmental exposure.

When the body is exposed to foreign organisms, such as bacteria and viruses, the immune system produces antibodies against them. Antibodies help the body recognise and kill the foreign organisms. The antibodies remain in the body to help protect the body against future infections with the same organism. This is known as active immunity.

Tuberculin is injected under the skin to test if a person already has antibodies to the tuberculosis bacterium. The tuberculin will be injected under the skin of the forearm, where it forms a pale wheal a few millimetres in diameter. This is called the Mantoux test. You will be asked to return to your doctor 48 to 72 hours after having the test so the results can be read.

If you already have antibodies to tuberculosis, they will recognise and attack the tuberculin under the skin. Over the 48 to 72 hours this will cause a skin reaction of a hard, dense, raised wheal (not always visible). Your doctor will measure the size of any skin reaction.

If the skin shows a strong reaction, it means that there has been previous exposure to tuberculosis bacteria. This might be due to a previous vaccination against tuberculosis (BCG), environmental exposure to the bacteria, or a current tuberculosis infection. The size of the reaction and other relevant information, such as if you have recently been in contact with someone with tuberculosis, if you have a high occupational risk of contracting the disease, or if you live in or have visited a high prevalence country, will help the doctor decide on the appropriate course of action.

What is it used for?

Aiding diagnosis of tuberculosis

Testing for previous BCG vaccination

Warning!

You may experience mild itching, swelling, or irritation at the site of the skin test. These are normal reactions that do not require any treatment. Try and avoid scratching the site. Keep the site clean and avoid putting creams, lotions, or adhesive dressings on it.

The reaction to tuberculin skin test may be suppressed by corticosteroid therapy, immunosuppressive treatment or diseases (eg HIV), live viral vaccines, glandular fever, sarcoidosis and viral infections including those of the upper respiratory tract. Tell your doctor if any of these apply to you when you have the skin test.

People who have a negative response to tuberculin (do not show a skin reaction) and who may have had an airway or other viral infection at the time of testing, should be re-tested two to three weeks after they recover from the infection, before being given a BCG vaccination. If a second tuberculin test is necessary it should be carried out on the other arm.

Not to be used in

No known conditions

This medicine should not be used if you are allergic to one or any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy. If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.

Pregnancy and Breastfeeding

Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.

Tuberculin skin testing should not be carried out during pregnancy or breastfeeding, unless considered essential by your doctor. Seek medical advice from your doctor.

Side effects

Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Because a side effect is stated here, it does not mean that all people using this medicine will experience that or any side effect.

Pain at the injection site

Itching around the area of injection

Ulceration at the injection site

Headache

Rash

Nausea

Fever (pyrexia)

Dizziness

Itchy rash (urticaria)

A general feeling of being unwell (malaise)

An extreme allergic reaction (anaphylaxis)

The side effects listed above may not include all of the side effects reported by the drug's manufacturer. For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.

How can this medicine affect other medicines?

Tuberculin skin tests should not be carried out within four weeks of receiving a live viral vaccine, for example measles, mumps and rubella (MMR), oral polio, rubella, yellow fever.

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