[citation needed] The "skin scratch test" as it is called, is not very commonly used due to the increased likelihood of infection.

[citation needed] Some allergies are identified in a few minutes but others may take several days.

A negative test does not conclusively rule out an allergy; occasionally, the concentration needs to be adjusted, or the body fails to elicit a response.

[6] The patch test uses rectangles of special hypoallergenic adhesive tape with different allergens on them.

The allergens on the patch include latex, medications, preservatives, hair dyes, fragrances, resins, and various metals.

[9] To prevent a severe allergic reaction, the test is started with a very dilute solution.

After 10 minutes, the injection site is measured to look for growth of wheal, a small swelling of the skin.

Physicians who perform skin test always have equipment and medications available in case an anaphylaxis reaction occurs.

The IgE antibody plays a vital role in allergies but its levels in blood do not always correlate with the allergic reaction.