During the screening visit, the study was fully explained to each patient's legal guardian and written informed consent was obtained. Whenever possible, patients provided assent. The screening visit also included: evaluating eligibility criteria; obtaining a medical history (including skin type, demographic data, and concomitant medications); obtaining a brief physical examination and urine pregnancy test (for females of childbearing potential), which had to be negative for the patient to enroll in the study; and providing patient education on how to assess pain using the Colored Analog Scale (CAS). The screening visit could occur on the same day as the procedure visit.