After a skin test, such as a tuberculin skin test (TST) for tuberculosis, you must return to the clinic 48 to 72 hours (2 to 3 days) later for a nurse to evaluate the results. A raised, red bump at the injection site indicates a positive reaction, suggesting the presence of the tested substance in your body. Do not cover the test site with a bandage.
Understanding the Post-Test Evaluation
The timeframe of 48-72 hours is crucial for accurate interpretation. During this period, the body's immune response to the injected substance, if present, will manifest as a visible reaction at the injection site. The nurse will measure the size and appearance of the reaction to determine the result.
- Positive Result: A firm, red bump indicates a positive reaction, suggesting the presence of the substance (e.g., tuberculosis bacteria in a TST). Further testing may be needed to confirm the diagnosis.
- Negative Result: The absence of a significant reaction suggests the absence of the substance.
- Indeterminate Result: In some cases, the reaction may be unclear, requiring further evaluation.
It's important to keep the appointment for follow-up evaluation. This crucial step ensures accurate interpretation of the test results and guides appropriate medical management.
