Pain Ease is marketed as a “non-drug” nonflammable topical anesthetic spray and is approved by the Food and Drug Administration for use on intact skin and mucous membranes and on minor open wounds. Its efficacy on nonglabrous skin has been demonstrated in a controlled randomized blinded trial in older children.34 Spray application is recommended over 4 to 10 seconds or until the skin blanches at a distance of 3 to 7 inches to avoid frostbite. The duration of the vapocoolant analgesia is short-lived,
approximately 60 seconds, because of rapid rewarming of the skin by cutaneous blood flow. A volunteer study involving application of vapocoolant stream spray to the forearm skin surface for 4 or 10 seconds duration and at 3 or 5 inches distance showed skin surface cooling below freezing temperature without tissue injury. Complete rewarming of the skin surface, subcutaneous and 1-cm intramuscular tissue, occurred within 4 to 5 minutes