Iontophoresis for anesthesia during pulsed dye laser treatment of port-wine stains

Non-invasive anaesthetic methods for dermatological laser procedures: a systematic review

Pain is a common side-effect of dermatological laser procedures. Non-invasive anaesthetic drugs and anaesthetic procedures can be used to provide pain relief and increase patient satisfaction and treatment efficacy. However, it remains unclear which method provides the best pain relief. The objective of this systematic review was therefore to assess the efficacy and safety of non-invasive anaesthetic methods during dermatological laser procedures. A systematic literature search was conducted. Randomized and non-randomized controlled clinical trials (RCTs and CCTs) were included. Two authors independently assessed study eligibility, extracted data and assessed the risk of bias. The quality of evidence was rated using Grading of Recommendations Assessment, Development and Evaluation (GRADE). Twenty RCTs and 12 CCTs were included, involving nine different laser indications: hair removal (n = 9), resurfacing/rejuvenation (n = 5), port wine stains (n = 8), leg telangiectasia (n = 3), facial telangiectasia (n = 2), tattoo removal (n = 2), naevus of Ota (n = 1), solar lentigines (n = 1) and HPV lesions (n = 1). The non-invasive anaesthetic methods (i.e. topical anaesthetic drugs, skin cooling, and pneumatic skin flattening [PSF]), types of lasers, laser settings, application time, and types of pain scales varied widely among the included studies. All of the studies had an unclear or high risk of bias, and the overall quality of evidence was rated as low. In general, active non-invasive anaesthetic methods seemed to provide favourable results compared to placebo or no anaesthesia, and topical anaesthetic drugs and PSF seemed to result in a better pain reduction than skin cooling. However, the current evidence is insufficient to provide recommendations for daily clinical practice. There is a need for more high-quality (head-to-head) RCTs. Future studies should also evaluate sex differences in pain perception, have uniformity with regard to validated pain measurement scales and address clinically significant differences in pain reduction besides statistically significant differences.

Comparison of skin conductance measurements and subjective pain scores in children with minor injuries

AIM

Objective measures of perceived pain may aid clinicians in decision-making regarding analgesia. This study aimed to assess the effectiveness of an algesimeter to assess the pain response of children to minor injury when compared with self-report.

METHODS

A commercially available skin conductance algesimeter was used to record pain in children presenting with a minor injury to a district general hospital. The recordings were compared with self-reported pain scores using the Wong-Baker FACES(®) Pain Rating Scale.

RESULTS

Sixty-seven children below 16 years of age (36 females, 53.7%, mean age 11.9 years, standard deviation 3.1 years) were assessed. There was a significant correlation between self-reported pain and number of fluctuations in skin conductance per second for girls (r = 0.325, p = 0.027), but not for boys (r = 0.160, p = 0.194). There was no significant association between self-reported pain and number of fluctuation in skin conductance per second and patient age.

CONCLUSION

There was a significant correlation between self-reported pain and the number of fluctuations in skin conductance in girls, but not boys. There may be a number of reasons for this gender variation, including difficulty in rating pain and lack of sensitivity in the pain rating scale.

Olfactory and trigeminal interaction of menthol and nicotine in humans

The purpose of the study was to investigate the interactions between two stimuli—menthol and nicotine—both of which activate the olfactory and the trigeminal system. More specifically, we wanted to know whether menthol at different concentrations modulates the perception of burning and stinging pain induced by nicotine stimuli in the human nose. The study followed an eightfold randomized, double-blind, cross-over design including 20 participants. Thirty phasic nicotine stimuli at one of the two concentrations (99 and 134 ng/mL) were applied during the entire experiment every 1.5 min for 1 s; tonic menthol stimulation at one of the three concentrations (0.8, 1.5 and 3.4 μg/mL) or no-menthol (placebo control conditions) was introduced after the 15th nicotine stimulus. The perceived intensities of nicotine’s burning and stinging pain sensations, as well as perceived intensities of menthol’s odor, cooling and pain sensations, were estimated using visual analog scales. Recorded estimates of stinging and burning sensations induced by nicotine initially decreased (first half of the experiment) probably due to adaptation/habituation. Tonic menthol stimulation did not change steady-state nicotine pain intensity estimates, neither for burning nor for stinging pain. Menthol-induced odor and cooling sensations were concentration dependent when combined with low-intensity nicotine stimuli. Surprisingly, this dose dependency was eliminated when combining menthol stimuli with high-intensity nicotine stimuli. There was no such nicotine effect on menthol’s pain sensation. In summary, we detected interactions caused by nicotine on menthol perception for odor and cooling but no effect was elicited by menthol on nicotine pain sensation.

Lidocaine iontophoresis for topical anesthesia before dermatologic procedures in children: a randomized controlled trial

Local anesthesia by injection in pediatric patients undergoing dermatologic procedures is not well received because of the pain of injection and the fear of needles. Lidocaine iontophoresis is a method of topical anesthesia where lidocaine is driven into the skin under the influence of electric current. We performed a prospective double-blind, placebo-controlled evaluation of iontophoresis of 2% lidocaine with 1:100,000 epinephrine. Sixty children requiring dermatologic procedures were enrolled (50 shave biopsy, 7 curettage, 2 injection, 1 punch biopsy). Twenty-nine of 31 patients in the lidocaine group versus 2 of 29 placebo patients required no supplemental anesthesia (p < 0.001). The pain reported by the patients on the Oucher pain scale subsequent to the procedure was significantly lower in the lidocaine group (p < 0.001). Investigators and parents also rated pain lower in the lidocaine group (p < 0.001). Blanching and/or erythema occurred in 58 of 60 patients, but resolved within 1 hour in all patients. There were no other adverse events. Lidocaine iontophoresis is a safe and effective method of topical anesthesia prior to dermatologic procedures in children.

Lidocaine iontophoresis for local anesthesia before shave biopsy

BACKGROUND

Lidocaine iontophoresis is a method of topical anesthesia in which lidocaine is driven into the skin under the influence of electric current.

OBJECTIVE

To compare lidocaine iontophoresis to placebo for topical anesthesia before shave biopsy in adult patients.

METHODS

This was a single-center, double-blind, placebo-controlled evaluation of iontophoresis of 2% lidocaine with 1:100,000 epinephrine in patients undergoing shave biopsy. Patients were evaluated for sensation to pinprick after iontophoresis. After completion of the procedure, those patients who did not receive supplemental lidocaine rated the pain associated with the procedure using a 10-cm visual analog scale. The investigator also evaluated the patient's pain after biopsy. Treatment sites were examined for evidence of adverse events such as erythema, urticaria, or burns.

RESULTS

Forty-one patients undergoing shave biopsy for evaluation of skin lesions were enrolled. Nineteen of 21 patients in the lidocaine group versus 2 of 20 placebo patients required no supplemental anesthesia (P<0.001). The pain reported by the patient on the visual analog scale subsequent to the procedure was significantly lower in the lidocaine group (P<0.001). In concordance with the results reported by the patients, investigators rated pain lower in the lidocaine group (P<0.001). Blanching and/or erythema occurring at the iontophoresis-treated site in 37 of 41 patients resolved within 1 hour. There were no other treatment-related events.

CONCLUSIONS

Lidocaine iontophoresis is a safe and effective method of administering topical anesthesia before shave biopsy in adult patients.

Topical anesthetics in children: agents and techniques that equally comfort patients, parents, and clinicians

Topical anesthetics are increasingly important, as the number of outpatient surgeries for dermatologic problems in infants and children is steadily growing. This noninvasive modality of anesthetic delivery in conjunction with a reassuring environment may minimize the discomfort of otherwise painful procedures. Since the 1880s, when cocaine was first used as a topical ophthalmologic anesthetic, many ester-and amide-based local anesthetics have been developed for a variety of simple and complex procedures. The pediatric dermatologist's arsenal of topical anesthetic preparations is increasing with the development of novel vehicles of transdermal delivery and the use of anesthetics in combination. Eutectic mixture of local anesthetics is currently the most frequently prescribed topical agent, though the use of ELA-max, another lidocaine-containing preparation, is gaining momentum, especially in the neonatal population. Amethocaine, tetracaine, iontophoresis, and the S-caine patch, a product on the horizon for use in the pediatric population, also are included in this discussion.

The pulsed dye laser for cutaneous vascular and nonvascular lesions

The pulsed dye laser was originally developed for the treatment of vascular lesions, especially hemangiomas and port-wine stains. The central concept of pulsed-dye laser is to preserving the epidermis by allowing hemoglobin to be more precisely targeted within lesions. More recently, the pulsed dye laser has also been used in the treatment of a wide spectrum of nonvascular lesions. Because of its safety profile, and its selectivity in targeting lesions, therapists can comfortably treat a wide variety of lesions in all age groups and anatomic sites.

Iontophoresis as a new method of delivering local anesthesia to the urethra: a pilot study

OBJECTIVES

To test the feasibility of using the iontophoretic catheter as a means of delivering local anesthetic (lidocaine hydrochloride) to the urethra for periurethral injection of collagen.

METHODS

Eight women with urodynamically proven genuine stress incontinence underwent periurethral collagen injections. Local anesthesia was provided by 4% lidocaine with 1 in 100,000 epinephrine administered over 10 minutes using an iontophoretic catheter. Pain was assessed by Likert and visual analogue scales. Cystoscopic appearance of the urethra was noted.

RESULTS

The periurethral bulking procedure was completed without further anesthetic in 7 women, 1 of whom had no pain. There was no evidence of urethral damage from the iontophoresis.

CONCLUSIONS

Iontophoresis shows promise as a method of providing analgesia to the urethra. However, the degree of analgesia is variable, and further research is needed on catheter design to ensure transport of anesthetic agent into the periurethral tissues.

Pediatric dermatologic surgery for the primary care pediatrician

Surgical procedures on the skin are commonplace in the practice of pediatric dermatology. Dermatologists are trained in their residencies to perform office surgery, including biopsies, excisions with repairs, cryosurgery, chemosurgery, and laser surgery. Although most dermatologists treat patients of all ages, some treat children only. Within this group, some are concentrating on pediatric dermatologic surgery. Many dermatologists take additional training in dermatologic and laser surgery, treating both adults and children. New techniques and developing technology present pediatricians and dermatologists with many options in choosing the best and most appropriate treatment modalities.