Laser-assisted penetration of topical anesthetic in adults.
OBJECTIVE
To determine whether pretreatment of skin with erbium:YAG (Er:YAG) laser-assisted delivery facilitates the penetration of lidocaine cream to provide anesthesia suitable for needlesticks after just 5 minutes.


METHODS
Trial 1 was a double-blind randomized controlled trial, whereas trial 2 was a nonblinded randomized controlled trial.


METHODS
The study was conducted in 2 facilities, an academic and a private clinical research unit.


METHODS
A total of 320 healthy volunteers, aged 18 to 65 years and of any Fitzpatrick skin phototype.


METHODS
Trial 1 involved an Er:YAG laser pretreatment to disrupt the stratum corneum followed by an application of 4% lidocaine cream on one arm, and a laser pretreatment plus placebo on the other arm. Trial 2 involved an application of 4% lidocaine cream alone on one arm, and a laser pretreatment followed by an application of 4% lidocaine cream on the other arm.


METHODS
Self-reported pain perception on a 100-mm visual analog scale after quick insertion and removal of a 25-gauge hypodermic needle on the treatment sites.


RESULTS
Data from the 2 trials showed that there was a 62% pain reduction with laser pretreatment plus lidocaine compared with laser pretreatment plus placebo, and a 61% pain reduction with laser pretreatment plus lidocaine, compared with lidocaine alone. The decrease in pain in both trials was statistically significant (P<.001). Adverse events reported 48 hours after treatment were few and mild.


CONCLUSIONS
Treatment with the Er:YAG laser followed by lidocaine cream is a safe, effective, and efficient means of inducing skin anesthesia that significantly reduces the pain of hypodermic needle insertion.
Department of Dermatology, University Hospitals of Cleveland/Case Western Reserve University, Cleveland, Ohio 44106, USA. edb4@po.cwru.edu
Elma D
ED
Baron
Lisbeth
L
Harris
William S
WS
Redpath
Howard
H
Shapiro
Fred
F
Hetzel
Grant
G
Morley
David
D
Bar-Or
Seth R
SR
Stevens
D000287:Administration, Topical; D000293:Adolescent; D000328:Adult; D000368:Aged; D000779:Anesthetics, Local / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000627:therapeutic use*; D003131:Combined Modality Therapy; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D053685:Laser Therapy; D008012:Lidocaine / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D016602:Needlestick Injuries / Q000150:complications*; D010146:Pain / Q000209:etiology / Q000517:prevention & control*; D010147:Pain Measurement; D012016:Reference Values; D012867:Skin / Q000187:drug effects / Q000528:radiation effects
D000779:Anesthetics, Local; D008012:Lidocaine