What Does a Positive TB Test Look Like?
Tuberculosis (TB) is a serious bacterial infection that can affect the lungs, as well as other parts of the body. The only way to determine if a person has TB is by taking a TB test. The TB test used most commonly is a tuberculin skin test (TST) also known as a Mantoux test. This test involves having a tiny amount of antigen injected just below the surface of the skin. If the skin has reacted positively to the antigen, it is an indication that the individual has a TB infection.
So, what does a positive Tuberculosis test look like?
Appearance of a Positive Tuberculosis Test
Usually, a positive Tuberculosis test will show up as a raised, red lump at the injection site. This is known as a ‘Tuberculin Skin Test (TST) Reaction’ . It is normal for the lump to be slightly itchy or scaly but it should not be painful. However, the size and redness of the lump can vary from person to person, so it is important to differentiate between a positive and negative test.
The larger the lump and the redder the skin is, the more likely it will be that the test is positive. Generally, if the lump is larger than 10mm in width, it is considered a positive result and will require further testing.
Interpreting a Positive Tuberculosis Test
A positive result from a Tuberculosis test does not necessarily mean that an individual has active TB. It is possible that the individual is simply infected with the TB bacteria, and does not currently have the disease. An individual with a positive Tuberculosis test should be tested for active TB infection with a chest x-ray, as well as other laboratory tests such as a sputum sample or blood test.
It is also important to remember that a positive Tuberculosis test does not mean that a person is contagious. It takes weeks, or possibly even months, for an individual with a positive Tuberculosis test to become contagious and to be able to spread the disease.
Treating a Positive Tuberculosis Test
If the Tuberculosis test result is positive, the individual should be treated immediately with a course of antibiotics. Treatment usually lasts several months, and failure to complete the course of antibiotics can lead to the infection becoming recurrent or even more serious.
If an individual has a confirmed case of TB, they may be referred to a specialist such as a pulmonologist or an infectious disease specialist. The specialist will help to monitor the patient’s progress and make sure that the TB treatment course is completed.
Conclusion
A positive Tuberculosis test will appear as a raised, red lump at the injection site which is larger than 10mm in width. If a positive test is detected, it is important to follow up with further tests, as well as starting a course of antibiotics. With the proper treatment and care, TB can be cured.