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 lidocaine/tetracaine cream and lidocaine/prilocaine cream for local anaesthesia during laser treatment of acne keloidalis nuchae and tattoo removal: results of two randomized controlled trials

BACKGROUND

Pain is a common adverse effect of dermatological laser procedures. Currently, no standard topical anaesthetic cream exists for deeper dermal laser procedures.

OBJECTIVES

To compare the efficacy of lidocaine/tetracaine cream and lidocaine/prilocaine cream in reducing self-reported pain during deeper dermal laser treatment of acne keloidalis nuchae (AKN) and tattoos.

METHODS

We conducted two randomized, double-blind, controlled clinical trials with intrapatient, split-lesion designs: study A included patients with AKN (n = 15); study B included patients with black tattoos (n = 15). The primary end point was the patients' self-reported pain on a 10-cm visual analogue scale (VAS). Secondary objectives were the percentage of patients with adequate pain relief, willingness to pay €25 for the cream that provided the best pain relief and safety of the creams.

RESULTS

In both studies, VAS scores were lower for lidocaine/prilocaine cream, with a mean VAS difference in study A of 1·9 [95% confidence interval (CI) 1·0-2·8] and in study B of 0·6 (95% CI -0·7 to 1·9). In study A, adequate pain relief was achieved in 13% (n = 2) with lidocaine/tetracaine cream vs. 73% (n = 11) with lidocaine/prilocaine cream (P = 0·004), and in study B in 53% (n = 8) vs. 80% (n = 12), respectively (P = 0·289). In study A, 47% (n = 7) were willing to pay an additional €25 vs. 73% (n = 11) in study B. No serious adverse events occurred.

CONCLUSIONS

Lidocaine/prilocaine cream under plastic occlusion is the preferred topical anaesthetic during painful laser procedures targeting dermal chromophores.

Lentigo maligna - anatomic location as a potential risk factor for recurrences after non-surgical treatment

Background

A higher incidence of lentigo maligna (LM) recurrences on the nose was previously observed in our cohort after non‐surgical treatment.

Objectives

To determine histological parameters that might be related to the previously observed higher incidence of LM recurrences on the nose after non‐surgical treatment.

Methods

We randomly selected 22 surgical specimens of LM on the nose and 22 on the cheek. Histopathological analysis was performed on haematoxylin and eosin stained and microphthalmia transcription factor immunohistochemically stained slides. The number of pilosebaceous units (PSU) per mm, maximum depth of atypical melanocytes along the skin appendages and maximum depth of the PSU itself were determined.

Results

The nose had a significantly higher density of PSU than the cheek. The atypical melanocytes extended deeper along the PSU on the nose with a mean (SD) depth of 1.29 mm (0.48) vs. a mean depth of 0.72 mm (0.30) on the cheek (P < 0.001). The maximum depth of the PSU on the nose was greater than on the cheek, mean (SD) depth of 2.28 mm (0.41) vs. 1.65 mm (0.82) (P = 0.003).

Conclusions

The higher recurrence risk of LM on the nose after non‐surgical treatment that we previously observed in our cohort is most likely based on a higher density of atypical melanocytes and also their deeper extension into the follicles. These results shed more light on our previous findings and learn that anatomical location is relevant for the risk of recurrence of LM after non‐surgical treatment.

Epidemiology of Lentigo Maligna and Lentigo Maligna Melanoma in the Netherlands, 1989-2013

Lentigo maligna (LM) is considered a precursor to LM melanoma (LMM). We assessed trends in LM and LMM incidence rates between 1989 and 2013 in the Netherlands, and estimated the risk of an LMM after LM. Data on newly diagnosed LM and LMM were obtained from the Netherlands Cancer Registry and PALGA: Dutch Pathology Registry. Age-standardized incidence rates (European standardized rate), estimated annual percentage changes, and the cumulative incidence of LMM after LM were calculated. Between 1989 and 2013, 10,545 patients were diagnosed with a primary LM and 2,898 with a primary LMM in the Netherlands. The age-standardized incidence rate for LM increased from 0.72 to 3.84 per 100,000 person-years, and for LMM from 0.24 to 1.19 between 1989 and 2013. LM incidence increased from 2002 to 2013 with 6.8% annually, before an even steeper rise in LMM incidence from 2007 to 2013 (estimated annual percentage change: 12.4%). The cumulative incidence of LMM after a primary LM after 25-year follow-up was 2.0% for males and 2.6% for females. The increased incidence of LM and LMM in the Netherlands seems, besides increased awareness and increased histological confirmation of LM, to reflect a true increase. The absolute risk of an LMM (at any location) after a histologically confirmed LM was low (2.0-2.6%).