Use of lidocaine-prilocaine cream for vaccination pain in infants

Purpose: To determine whether use of lidocaine-prilocaine 5% cream (EMLA) decreases pain associated with diphtheria-pertussis-tetanus (DPT) vaccination in infants. Methods: Randomized, double-blind, controlled trial in outpatient pediatric practice, Toronto, Ontario, Canada. Before vaccination, parents applied 2.5 gm of EMLA or placebo to the infant's leg and covered it with an occlusive dressing for at least 60 minutes. The infant received a 0.5 ml intramuscular injection of DPT at 2° to 8°C with a 1.6 cm 25-gauge needle; the infant was videotaped. The Modified Behavioral Pain Scale (MBPS) was used to assess baseline and postvaccination pain scores. Latency and duration of infant cry were also measured. Results: A total of 49 evaluable infants received EMLA, and 47 infants received placebo. There were no significant differences in demographic data; mean age was 5 months; and 50% of the subjects were male. The median difference in prevaccination and postvaccination MBPS scores was lower for EMLA than for placebo (p=0.001). The latency to the first cry was longer for subjects who were treated with EMLA (p=0.0004), but the total crying time was shorter (10.3 seconds vs 25.2 seconds; p=0.027). Of the study group, 90% (45/50) of subjects treated with EMLA and 12% (6/49) of subjects treated with placebo had local skin reactions (p<0.0001), mainly skin blanching. Conclusions: Pretreatment with EMLA decreases infant pain from DPT vaccinations. Application of these data is limited to healthy infants receiving DPT vaccinations.