Tulehdustaesterä

Tulehdustaesterä, also known as the "tuberculin test," is a diagnostic procedure used to detect exposure to Mycobacterium tuberculosis, the bacterium that causes tuberculosis (TB). The test involves injecting a small amount of purified protein derivative (PPD) from the bacterium into the skin. The PPD is derived from the tubercle bacillus and is used as an antigen to stimulate an immune response in individuals who have been exposed to the bacterium.

The test is typically performed by injecting 0.1 milliliters of PPD into the upper arm or forearm. The area is then observed for a reaction, which usually appears within 48 to 72 hours. A positive reaction is indicated by the formation of a raised, red area (induration) at the injection site, typically 5 to 15 millimeters in diameter. The size and appearance of the reaction can vary depending on the individual's immune response and the amount of PPD used.

The tuberculin test is considered a screening tool rather than a definitive diagnosis. A positive result indicates that the individual has been exposed to the bacterium, but it does not confirm active TB disease. Additional diagnostic tests, such as chest X-rays, sputum tests, and blood tests, may be required to determine the presence of active TB.

The tuberculin test is widely used due to its simplicity, low cost, and ability to detect past exposure to TB. However, it has limitations, including the potential for false-positive and false-negative results, especially in individuals with certain medical conditions or those who have been vaccinated against TB. Therefore, the test should be interpreted with caution and in conjunction with clinical evaluation.