Skin prick test Intradermal test Wheal Wheal (1:10 dilution) Wheal (1:5 dilution) Control         Histamine 4 × 4 mm 4 × 4 mm     Saline negative     Esters         Procaine negative 5 × 7 mm   Amides         Lidocaine negative 4 × 7 mm     Mepivacaine  negative 8 × 7 mm     Bupivacaine negative 3 × 4 mm 6 × 7 mm   Ropivacaine negative negative Negative

Table 1: Wheal size of skin prick test and intradermal test for local anesthetics.