Intradermal skin testing is more sensitive than the epicutaneous skin tests, but it is generally only performed if the epicutaneous test is negative. The test is performed using 25 to 27 gauge needles. A small amount of allergen extract (0.02-0.05 ml: 0.02 mL in Hymenoptera to avoid false-positive) is injected into the skin, creating a small bled 2-3 mm in diameter. Spaces between each injection site should be >2 cm. For patients with a negative prick-puncture test, the concentration of extract for intradermal testing should be between 100- and 1,000 fold more dilute than the concentration used for epicutaneous testing.