Side Effects of a TB Test

Pulmonary tuberculosis, or TB, is a bacterial infection of the lungs that can spread to other areas of the body. Although most cases of TB can be treated with antibiotics, early diagnosis is important for easier recovery. The Mantoux skin test is used to discover if a person has TB.

Definition

• The Mantoux skin test involves injecting a small amount of a liquid called purified protein derivative (PPD) under the skin on the forearm. The skin is checked for a reaction 48 to 72 hours later to determine if a person has been exposed to tuberculosis or possibly has an active case of the disease.

Results

• A negative skin test result means that there was no reaction to the PPD. A positive result is usually indicated by measuring the level of hard swelling at the injection site. If the level of hard swelling is high enough, another skin test might be done, and a chest X-ray will be taken to determine if the TB is active or inactive.

Side Effects

• A TB skin test might result in minor side effects, including swelling, itching or tenderness at the injection site. These effects should go away within a week.

More Severe Reactions

• On rare occasions, such as in people who are sensitive to PPD, more serious side effects might occur. Some people can experience fever, swollen glands, skin rashes or ulcers on the skin at the testing site. Severe redness and swelling can also occur, although such reactions are unusual.

  The TB skin test will not make a person sick with tuberculosis.

Treatment

• For someone who is diagnosed with inactive TB, a doctor will likely recommend treatment with antibiotics for six to nine months to kill off the bacteria. A person with active TB is treated with several antibiotics at once. For successful treatment, it is important that the patient take all of the medication prescribed.