Children usually get the test done on their upper back. If possible, discontinue any oral or nasal antihistamine medications for at least 72 hours prior to the test, otherwise these medications can impede skin testing results and cause false negative results. [3] X Expert Source Farah Khan, MDBoard Certified Allergist & Immunologist Expert Interview. 5 January 2022.
The test will not be painful, as the lancets will just barely pierce your skin. There should be no blood and you should feel a mild discomfort at most.
They will also apply a glycerin or saline solution to determine if you have sensitive skin. Your doctor will then keep your sensitive skin in mind when they review the results of the test.
The skin injection will not be very deep so it should not be painful.
You will need to wear the patch for 48 hours and avoid bathing or doing strenuous activity that could cause you to sweat.
Allergy skin tests are more accurate when they are left on for at least 15 minutes and no longer than 40 minutes. If you received a patch test, it may take at least 48 hours for any allergic reactions to appear. You may need to return to your doctor’s office to get the results of the test.
If you are allergic to multiple substances, you may have multiple wheals. Wheals that are smaller than 3 millimetres (0. 12 in) in diameter may not be a sign of an allergic reaction.
The presence of flares and no wheals may mean your skin is irritated by the substance, but you are not allergic to it.
If you have very large wheals due to an allergen, you may have a high level of sensitivity to a substance or food. Your doctor will let you know which substances you tested positive for in terms of an allergy.
Usually if you test positive for an allergy to a substance more than once, it means you are allergic to it.
For example, if you have a mild allergy to cats, your doctor may recommend you stay away from cats and take allergy medication before you interact with cats. Or if you have a severe allergy to peanuts, your doctor may suggest you avoid eating peanuts and confirm foods do not have peanuts before you eat them. For some allergens, you may have a very minor reaction, such as a rash or skin irritation. But if you continue to expose yourself to the allergen, your reactions may get worse over time. Try to avoid being around any allergens so you stay healthy.
