Immune response to Leishmania infection in human skin

Intracellular IFN-γ and IL-4 levels of CD4 + and CD8 + T cells in the peripheral blood of naturally infected (Leishmania infantum) symptomatic dogs before and following a 4-week treatment with miltefosine and allopurinol: a double-blinded, controlled and cross-sectional study

BACKGROUND

Canine leishmaniosis (CanL) is a systemic disease caused by the protozoan parasite Leishmania infantum with a wide spectrum of clinical signs, with cutaneous, ocular, renal and lymphoreactive conditions prevailing in the clinical setting. The immune system plays a pivotal role in the evolution of Leishmania infection and its response to antileishmanial treatment. Cytokines are important immune response mediators that are released by activated lymphocytes and less so by other immunocytes. In dogs with leishmaniosis, IFN-γ and IL-4 have been recognized as the main activators of cellular and humoral immunity, respectively. The objective of this study was to investigate intracellular IL-4 and IFN-γ expression by CD4 + and CD8 + lymphocytes in the peripheral blood of symptomatic dogs before and after combined antileishmanial treatment with miltefosine and allopurinol.

RESULTS

Postantileishmanial treatment CD4 + IL-4 + and CD8 + IL-4 + cell counts were significantly decreased, although no similar changes were observed in the comparisons made between the pre- and posttreatment CD4 + IFN-γ + and CD8 + IFN-γ + counts and ratios.

CONCLUSION

The findings indicate that IL-4 production by T cells may facilitate the symptomatic phase of CanL, whereas IFN-γ production by CD4 + and CD8 + cells may indicate its negligible role in the evolution of natural CanL and perhaps the equivocal positive influence of antileishmanial treatment.

Related Pentacyclic Triterpenes Have Immunomodulatory Activity in Chronic Experimental Visceral Leishmaniasis

Leishmaniasis is a neglected tropical disease caused by the flagellated protozoa of the genus Leishmania that affects millions of people around the world. Drugs employed in the treatment of leishmaniasis have limited efficacy and induce local and systemic side effects to the patients. Natural products are an interesting alternative to treat leishmaniasis, because some purified molecules are selective toward parasites and not to the host cells. Thus, the aim of the present study was to compare the in vitro antileishmanial activity of the triterpenes betulin (Be), lupeol (Lu), and ursolic acid (UA); analyze the physiology and morphology of affected organelles; analyze the toxicity of selected triterpenes in golden hamsters; and study the therapeutic activity of triterpenes in hamsters infected with L. (L.) infantum as well as the cellular immunity induced by studied molecules. The triterpenes Lu and UA were active on promastigote (IC₅₀ = 4.0 ± 0.3 and 8.0 ± 0.2 μM, respectively) and amastigote forms (IC₅₀ = 17.5 ± 0.4 and 3.0 ± 0.2 μM, respectively) of L. (L.) infantum, and their selectivity indexes (SI) toward amastigote forms were higher (≥13.4 and 14, respectively) than SI of miltefosine (2.7). L. (L.) infantum promastigotes treated with Lu and UA showed cytoplasmic degradation, and in some of these areas, cell debris were identified, resembling autophagic vacuoles, and parasite mitochondria were swelled, fragmented, and displayed membrane potential altered over time. Parasite cell membrane was not affected by studied triterpenes. Studies of toxicity in golden hamster showed that Lu did not alter blood biochemical parameters associated with liver and kidney functions; however, a slight increase of aspartate aminotransferase level in animals treated with 2.5 mg/kg of UA was detected. Lu and UA triterpenes eliminated amastigote forms in the spleen (87.5 and 95.9% of reduction, respectively) and liver of infected hamster (95.9 and 99.7% of reduction, respectively); and UA showed similar activity at eliminating amastigote forms in the spleen and liver than amphotericin B (99.2 and 99.8% of reduction). The therapeutic activity of both triterpenes was associated with the elevation of IFN-γ and/or iNOS expression in infected treated animals. This is the first comparative work showing the in vitro activity, toxicity, and therapeutic activity of Lu and UA in the chronic model of visceral leishmaniasis caused by L. (L.) infantum; additionally, both triterpenes activated cellular immune response in the hamster model of visceral leishmaniasis.

A rare case of leishmaniasis recidiva cutis evolving for 31 years caused by Leishmania tropica

A 64-year-old woman presented with erythematous, infiltrative plaques with a central atrophic area on both zygomatic regions. Several yellow-reddish papules were seen at the periphery of the plaques and showed an "apple-jelly" color on diascopy (Fig. 1). No visceral involvement was detected. The past medical history revealed that, at 3 years of age, she had developed an "Oriental sore" on both cheeks that healed with permanent scars. Thirty years later, she noticed an erythematous patch around the scars. She reported a hospital admission 22 years earlier for cutaneous leishmaniasis (CL); this was treated with pentavalent antimonial therapy for 10 days with partial improvement, when she refused further treatment. The lesions worsened in the summer and gradually became disfiguring, which prompted her to seek medical consultation. Laboratory findings were normal. Leishmania antibody titers were negative. Tissue samples were obtained by biopsy from the border of the lesion for culture, polymerase chain reaction (PCR), and histopathologic examination. Histology revealed a dermal infiltrate with tuberculoid granulomas surrounded by lymphocytes, histiocytes, and some plasma cells, but no caseation necrosis. A few Leishmania organisms were found on careful searching (Fig. 2). Leishmania tropica was identified by culture and PCR. A diagnosis of leishmaniasis recidiva cutis (LRC) was made on the basis of the anamnestic data together with the clinical, histopathologic, biologic, and molecular findings. Complete regression was achieved with meglumine antimoniate (Glucantime) given intramuscularly (15 mg Sb(V)/kg/day for 15 days) and cryosurgery with liquid nitrogen. No recurrence was noted during a 12-month follow-up period.

Cutaneous leishmaniasis

Cutaneous leishmaniasis is a widespread tropical infection caused by numerous different species of Leishmania protozoa that are transmitted by sandflies. Its clinical presentations are extremely diverse and dependent on a variety of parasite and host factors that are poorly understood. Diagnosis should aim to identify the exact species involved, but this requires laboratory investigations that are not widely available. No single ideal treatment has been identified, and those available are limited by variable success rates and toxicity. Clinical guidelines are needed to make better use of the investigations and treatments that do exist. Prevention is currently limited to bite prevention measures.

Laser hair removal

Since 1996, there have been numerous advances in hair laser removal that utilize melanin as a chromophore. All of the devices on the market may be used in patients with light skin (phototypes I-III) and yield hair reduction near 75%. The ruby (694 nm) laser, alexandrite (755 nm) laser, and diode (810 nm) laser, as well as intense pulsed light are commonly used devices for hair laser removal. The long-pulsed Nd:YAG (1064 nm) laser represents the safest device for hair removal in dark-skinned patients because of its long wavelength, although the diode laser, alexandrite laser, and intense pulse light may be used. For treatment of light hair, combination radiofrequency and optical devices as well as photodynamic therapy are under investigation.

Leishmaniasis cutánea

Leishmaniases are diseases caused by infection by protozoa of the genus Leishmania. Cutaneous leishmaniasis caused by Leishmania infantum is frequent in Spain, especially in certain geographic areas. Diagnosis of cutaneous leishmaniasis is difficult because of the varied symptoms and because making cultures of this parasite is complicated. There are also different therapeutic, medical and surgical options, none of which is fully satisfactory. We review the most significant agents of cutaneous leishmaniasis in Spain.

Hair reduction using intense pulsed light source

BACKGROUND

Long-term hair removal in hirsute women remains a challenging issue. Various laser and laser-like devices are currently in use for hair removal, but little is known about the permanence of their results. This study deals with the permanence of hair removal using the intense pulsed light source (IPLS).

OBJECTIVE

To test the effectiveness in long-term hair reduction.

METHODS

Seventy female hirsute patients were selected in the Department of Laser Therapy at the Medical Center, Maastricht, the Netherlands. The average age of the mostly dark-haired patients of various skin types (Fitzpatrick I to V) was 41 years. They were subjected to a mean of 8 treatments (range of 2 to 23) followed for a mean period of 27.3 months.

RESULTS

Using the IPLS, 87% hair removal was achieved, whereby the number of treatments correlated with the amount of hair lost. No correlation was found between hair removal and patient-related or technical data. Minimal side effects occurred in 10% of the patients.

CONCLUSION

The IPLS system with its broad range of technical variables is effective in achieving long-term hair removal.

Comparing 18- Versus 12-mm Spot Size in Hair Removal Using a Gentlease 755-nm Alexandrite Laser

BACKGROUND

Laser epilation is based on the principle of selective photothermolysis, absorption of laser energy by the target chromophore melanin. It is claimed that larger spot sizes may be more effective for hair removal at identical fluences.

OBJECTIVE

To compare the efficacy of 18- vs. 12-mm spot size in hair removal using a Gentlelase Alexandrite laser from Candela Corporation (Boston, MA).

METHODS

In this double-blind, randomized control trial, patients underwent laser-assisted hair removal on the axillary region. Regions were randomly selected and treated with either an 18- or a 12-mm spot size. Three treatments at 6-week intervals with a 755-nm Gentlelase Alexandrite laser (Candela Corp., Canton, MA) at a fluence of 16 J/cm(2) with cooling and delay times of 60 ms. Hair counts were taken before each treatment session and compared. The mean percentage hair reduction and student's paired t-test were used to compare 18 versus 12 mm versus control sites at each visit and compared it with the baseline hair count.

RESULTS

There was a 10.3% difference in mean reduction favoring the 18-mm spot size treated area at the 6-month follow-up.

CONCLUSION

Our results indicate that a larger spot size appears to be more effective for laser assisted hair removal.

Long-Pulsed 1064-nm Nd:YAG Laser-Assisted Hair Removal in All Skin Types

BACKGROUND

Although there are several different laser systems available for the reduction of unwanted hair, no single system has been shown to be superior in providing safe and effective hair removal in every skin type. The purpose of this study was to evaluate the safety and efficacy of a high-energy, long-pulsed, 1064-nm Nd:YAG laser with a contact cooling device for hair removal in skin phototypes I-VI.

METHODS

Thirty-six adult patients (skin phototypes I-VI) with dark terminal facial or nonfacial hair were treated with a long-pulsed Nd:YAG laser (1064 nm, 10-mm spot size, fluence of 30 to 60 J/cm2). The selected pulse duration was dependent on the skin type of the patient: Skin types I/II, III/IV, and V/VI received 10, 20, and 30 ms, respectively. Three consecutive laser treatments were delivered to 36 skin sites at 4- to 6-week intervals. Hair counts and photographic evaluations of skin sites were obtained at baseline, immediately before each treatment session, and at 1, 3, and 6 months after the final laser treatment.

RESULTS

Peak hair reduction was observed 1 month after the series of laser treatments with a mean hair reduction ranging from 58% to 62% on facial sites and 66% to 69% on nonfacial sites. At 6 months after a series of three long-pulsed Nd:YAG laser treatments, a mean hair reduction of 41% to 46% on the face and 48% to 53% on the body was found depending on the skin phototype. Adverse reactions included mild to moderate treatment pain, short-term erythema, and rare occurrences of transient pigmentary alteration without scarring.

CONCLUSION

The long-pulsed 1064-nm Nd:YAG laser with contact cooling is a safe and effective method of hair reduction in patients of all skin types. Side effects were limited and transient.

Laser-assisted hair removal in Asian skin: efficacy, complications, and the effect of single versus multiple treatments

BACKGROUND

Alexandrite laser hair removal can be quite successful in lighter skin types. Effective hair removal in Asians can be difficult, and multiple treatments are usually required for effective treatment.

OBJECTIVE

To evaluate the safety and efficacy of alexandrite laser hair removal in Asian skin, to determine the benefit of multiple treatments, and to evaluate the value of test patches before laser treatment.

METHODS

One hundred forty-four Asian subjects with Fitzpatrick skin types III to V were treated with a cooled 40-ms alexandrite laser with fluences of 16 to 24 J/cm2. Initially, all treated subjects underwent test patch application. After test patch application, 35 subjects with 66 anatomic sites received three treatments. Thirty-five subjects with 66 anatomic sites received two treatments, and 74 subjects with 124 anatomic received a single treatment. All subjects were followed for 9 months after their final treatment.

RESULTS

In subjects that were treated three times, a 55% hair reduction was noted at 9 months after the third treatment. In subjects treated two times, a 44% hair reduction was noted at 9 months after the second treatment. In subjects treated only one time, a 32% hair reduction was noted at 9 months after the single treatment. No subjects had scarring or long-term pigmentary changes. There appeared to be no correlation between test patch acute complications and those seen after actual treatments.

CONCLUSION

Although Asian skin can be effectively treated with a cooled, long-pulsed alexandrite laser, complications do occur. Laser hair removal efficacy was increased with multiple treatments. There does not appear to be an exact correlation in Asian skin between complications occurring after test patch treatment and those seen with subsequent treatments.

Treatment of trichostasis spinulosa in skin phototypes III, IV, and V with an 800-nm pulsed diode laser

BACKGROUND

: Trichostasis spinulosa (TS) is a common follicular disorder that results from the retention of multiple vellus hairs within pilosebaceous follicles. A variety of treatment modalities have been used with variable but largely transient success.

OBJECTIVES

: To determine whether a pulsed diode laser irradiation would provide a therapeutic response to TS for a prolonged period.

METHODS

: Thirteen subjects with untreated TS and skin phototypes III, IV, and V were treated with a 800-nm pulsed diode laser at fluences ranging from 24 to 40 J/cm2 (mean, 36 J/cm2) and a 12- to 20-ms (mean 18 ms) pulse width. Two treatments were delivered at 4-week intervals. Evaluation of improvement was performed at 4 and 20 weeks after the last treatment by a blinded assessment of clinical photographs.

RESULTS

: Complete clearing of the lesions was achieved for a period of 8 to 12 weeks. A decrease in dark-plug appearance of greater than 50% was noted in half of the subjects 20 weeks after the second treatment. No pigmentary changes and scarring occurred in any subjects.

CONCLUSION

: Pulsed diode laser proved to be a safe and long-term effective treatment for TS in dark-skinned individuals.

Intermittent cryogen spray cooling for optimal heat extraction during dermatologic laser treatment

Fast heat extraction is critically important to obtain the maximal benefit of cryogen spray cooling (CSC) during laser therapy of shallow skin lesions, such as port wine stain birthmarks. However, a film of liquid cryogen can build up on the skin surface, impairing heat transfer due to the relatively low thermal conductivity and higher temperature of the film as compared to the impinging spray droplets. In an attempt to optimize the cryogen mass flux, while minimally affecting other spray characteristics, we apply a series of 10 ms spurts with variable duty cycles. Heat extraction dynamics during such intermittent cryogen sprays were measured using a custom-made metal-disc detector. The highest cooling rates were observed at moderate duty cycle levels. This confirms the presence, and offers a practical way to eliminate the adverse effect of liquid cryogen build-up on the sprayed surface. On the other hand, lower duty cycles allow a substantial reduction in the average rate of heat extraction, enabling less aggressive and more efficient CSC for treatment of deeper targets, such as hair follicles.

Laser hair removal with alexandrite versus diode laser using four treatment sessions: 1-year results

BACKGROUND

Laser hair removal is the treatment of choice for hypertrichosis. The two most commonly used hair removal lasers are compared.

OBJECTIVE

To present the results of a comparative study examining the role of wavelength, fluence, spot size, pulse width, and cooling systems on long-term results after a series of four laser hair removal treatments using the 755 nm alexandrite and 800-810 nm diode lasers.

METHODS

The axillae of 15 untanned, type I-V patients were treated side by side four times at 4- to 6-week intervals with a 755 nm, 3-msec pulse width, cryogen spray-equipped alexandrite laser and an 800 nm, variable pulse width, cooled sapphire window-equipped diode laser. Each patient was pretested and treated with the maximum fluence tolerated at the largest spot size available for each laser (12 mm round/113 mm2 for the alexandrite and 9 mm for the diode).

RESULTS

Evaluations were done at 3, 6, 9, and 12 months after the last treatment. Twelve-month results with the alexandrite and diode lasers achieved 85% versus 84% hair reduction. The fact that tan avoidance was strictly followed permitted the use of relatively high fluences (25-30+ J/cm(2)) even in type IV patients. For most patients, four treatment sessions using high fluences (30-40 J/cm(2)) with relatively large spot sizes (12 mm round for the 755 nm alexandrite and 9 mm for the 800 nm diode) resulted in 12-month hair reductions in the 90% range.

CONCLUSION

Both the alexandrite and diode lasers in this 12-month study produced excellent long-term hair reductions.

An in vivo study comparing the efficacy and complications of diode laser and long-pulsed Nd:YAG laser in hair removal in Chinese patients

BACKGROUND

Lasers with long wavelengths are less well absorbed by melanin and are considered to be particularly suitable for hair removal in dark-skinned patients.

OBJECTIVE

To compare the efficacy and complications of 800 nm diode and long-pulsed 1064 nm Nd:YAG lasers in laser-assisted hair removal in Chinese patients.

METHODS

Fifteen women had hair removal treatments (13 axillae and 2 legs) with diode laser on one side and Nd:YAG laser on the other. They were followed up for 36 weeks. Subjective assessments included the degree of immediate pain and the degree of hair regrowth. Clinical photographs were taken for evaluation by two independent observers to assess complications and the degree of hair regrowth.

RESULTS

Long-pulsed Nd:YAG laser was found to be significantly associated with a greater degree of immediate pain after laser surgery (P =.0001, independent sample t-test) and also had a longer laser time (P =.0001, independent sample t-test). Besides transit adverse effects such as erythema and perifollicular edema, only one patient developed hypopigmentation at week 6 which resolved by week 36. Although regrowth rates were low at week 6 (subjective rates were 23% and 19% for Nd:YAG and diode laser, respectively), most patients had significant regrowth at week 36 (subjective regrowth rate 91% for both long-pulsed Nd:YAG and diode lasers).

CONCLUSION

Diode 800 nm and Nd:YAG 1064 nm lasers are safe in laser-assisted hair removal in Chinese patients, and besides immediate pain, there was no other significant adverse effect. Most patients experienced regrowth 36 weeks after a single treatment. Further study is necessary to determine the long-term clinical efficacy and complications of laser-assisted hair removal with these systems in dark-skinned patients.

Laser hair removal: long-term results with a 755 nm alexandrite laser

BACKGROUND

Hypertrichosis is a common problem for which laser hair removal is becoming the treatment of choice. Optimal wavelength, pulse duration, spot size, fluence, and skin cooling parameters for various skin types have not yet been firmly established.

OBJECTIVE

To evaluate the long-term efficacy and safety of a 3-msec 755 nm alexandrite laser equipped with a cryogen cooling device for patients with Fitzpatrick skin types I-V.

METHODS

Eighty-nine untanned patients with skin types I-V underwent a total of 492 treatments of laser hair removal over a 15-month period. Each patient in the study underwent a minimum of three treatment sessions spaced 4-6 weeks apart (mean treatments 5.6). Retrospective chart review and patient interviews were used to establish hair reduction results. Treatment sites included the axillae, bikini, extremities, face, and trunk. A 3-msec pulse width, 755 nm alexandrite laser equipped with a cryogen spray cooling device was used in this study. Spot sizes of 10-15 mm were used. A spot size of 10 mm was used for fluences greater than 40 J/cm(2), a spot size of 12 mm was used for fluences of 35-40 J/cm(2), and spot sizes of 12 and 15 mm were used for fluences less than 30 J/cm(2). Fluences ranging from 20 to 50 J/cm(2) (mean fluence 36 J/cm(2)) were used.

RESULTS

The patients had a mean 74% hair reduction. Skin type I patients had an average of 78.5% hair reduction using a mean fluence of 40 J/cm(2) (35-50 J/cm(2)) and a 10-12 mm spot size (12 mm in more than 95% of treatments). Skin type II patients had a mean 74.3% hair reduction using a mean fluence of 38 J/cm(2) (30-40 J/cm2) and a 12-15 mm spot size. Skin type III patients had a mean 73.4% hair reduction using a mean fluence of 37 J/cm(2) (25-40 J/cm(2)) and a 12-15 mm spot size. Skin type IV patients had a mean 71.0% hair reduction using a mean fluence of 31 J/cm2 (25-35 J/cm(2)) and a 12-15 mm spot size. A patient with skin type V had a 60% hair reduction using a mean fluence of 23 J/cm(2) (20-25 J/cm(2)) and a 12-15 mm spot size. The efficiency of hair removal directly correlates significantly with the fluence used. Rare side effects included transient postinflammatory hyperpigmentation (n = 9; 10%), burn with blisters (n = 1; 1%), and postinflammatory hypopigmentation (n = 2; 2%). All complications resolved without permanent scarring.

CONCLUSION

The 3-msec cryogen cooling-equipped alexandrite laser can safely and effectively achieve long-term hair removal in patients with skin types I-V. The best results are achieved in untanned patients with skin types I-IV.

Histologic features seen in changing nevi after therapy with an 810 nm pulsed diode laser for hair removal in patients with dysplastic nevi

BACKGROUND

The majority of lasers used for hair removal target melanin as the chromophore. In contrast with other cutaneous applications of lasers, lasers used for hair removal must generate a limited, controlled degree of thermal damage to permanently remove hairs.

AIM

To remove excess back hair from two male patients, one with a history of multiple nevi, and prior biopsies showing features of dysplastic nevi, and the other with large nevi greater than 6 mm in diameter and a family history of malignant melanoma.

METHODS

Both patients received monthly treatments with an 810 nm, pulsed, high-power diode laser using a fluence of 20 J/cm2 and 25-30 J/cm2, respectively, and a pulse duration of 30 ms.

RESULTS

Both patients presented 1 month after their last treatment with changing nevi within the treatment areas. Neither patient had clinical inflammation or other alterations suggestive of change in the nevi related to treatment. Thus, the nevi were excised with no mention of the previous laser treatment. The histologic features in all nevi were similar. There was subepidermal blister formation with elongation and disruption of nevus cells. There was homogenization of the collagen within the papillary dermis in all lesions. Only small foci of nevus cells could be identified in the dermis in some of the biopsy specimens. In these biopsy specimens, the dermal stromal matrix homogenization extended into the reticular dermis.

CONCLUSIONS

Laser targeting of nevus cells and surrounding structures may produce clinically atypical nevi in areas previously treated for hair removal. This should be kept in mind, especially in patients with a history of dysplastic nevi or with a personal or family history of malignant melanoma.

Hair reduction using a scanning 800 nm diode laser

BACKGROUND

Numerous lasers are currently available for hair removal, yet there are still few studies that have examined the role of fluence, light dose, hair color, and treatment number in laser hair reduction.

OBJECTIVE

To demonstrate the efficacy and safety of a scanning 800 nm diode laser for hair reduction.

METHODS

An 800 nm scanning diode laser was used to deliver 24, 38, or 48 J/cm2 to a 3 cm x 3 cm area of skin located on the back, groin/bikini area, or thigh in 36 adult patients with varying shades of brown or black hair. Patients received one to four treatments during the course of the study. Hair loss was evaluated at both 30 and 90 days after final treatment. Biopsies were obtained from 20 consenting patients.

RESULTS

Significant fluence-dependent hair reduction was demonstrated between treatment and control groups. At 48 J/cm2, the highest dose, a mean hair reduction of 43% was achieved 30 days after the final treatment, and 34% was achieved 90 days after the final treatment. Darker hairs were more effectively treated than lighter hairs.

CONCLUSIONS

Hair reduction can be safely and effectively achieved using a scanning 800 nm diode laser.

An in vivo trial comparing the use of different types of 532 nm Nd:YAG lasers in the treatment of facial lentigines in Oriental patients

BACKGROUND

Versapulse is a system that consists of four laser modalities and was developed with the aim of increasing cost-effectiveness. However, as these lasers share a common power supply, for the Q-switched (QS) Nd:YAG 532 nm laser a large spot diameter is necessary to lower the fluence to a suitable level. This can increase the risk of hyperpigmentation when used for the treatment of lentigines in dark-skinned patients.

OBJECTIVE

The aim of our study was to access the clinical efficacy and the complication rate of the Versapulse QS Nd:YAG 532 nm laser, the Versapulse long-pulsed Nd:YAG 532 nm laser (without the chill tip), and a conventional QS Nd:YAG 532 nm laser in the treatment of lentigines in Chinese patients.

METHODS

Thirty-four Chinese patients with lentigines were randomized to receive laser surgery, with one side of the face treated by one laser and the other side treated by a different system. Patients were monitored for 6 weeks to assess the degree of clearing, hyperpigmentation, hypopigmentation, and erythema. Assessments involved patients interviewed using a visual analog questionnaire and two blinded observers who evaluated the pre- and posttreatment clinical photographs.

RESULTS

The Versapulse QS Nd:YAG 532 nm laser was associated with a statistically higher risk of complications. The Versapulse long-pulsed Nd:YAG 532 nm laser was compatible with the conventional QS Nd:YAG 532 nm laser in terms of clinical efficacy and complication rates.

CONCLUSION

The Versapulse long-pulsed 532 nm laser is more effective and should be used instead of the Versapulse QS Nd:YAG 532 nm laser for the treatment of lentigines in dark-skinned patients.

Topical anesthesia for laser hair removal: comparison of spot sizes and 755 nm versus 800 nm wavelengths

BACKGROUND

The Candela alexandrite and the Coherent diode laser systems come equipped with built-in skin cooling systems that are designed to both protect the epidermis, allowing higher fluences, and to alleviate discomfort. Nevertheless, pain can be a significant problem especially with treatment of larger areas. Scatter of the laser beam is reportedly affected by the spot size. It is claimed that larger spot sizes are more effective at identical fluences.

OBJECTIVE

This study evaluated the effectiveness of a topical 5% lidocaine cream (ELA-Max) to control pain and compared pain levels at identical fluences between the 8 mm and 12 mm spot size of the alexandrite laser and between the alexandrite and diode laser with its 9 mm spot size.

METHODS

The study was conducted in the axillae of 12 patients. Each axilla was divided in half for side-by-side comparison. Half of the right axilla was treated with the alexandrite 8 mm and the other half with the 12 mm spot size at identical fluences. The left axilla was treated at the maximum tolerated fluences with the alexandrite 12 mm spot size and the diode 9 mm spot size.

RESULTS

At identical fluences and other parameters, there was significantly more pain with the alexandrite 12 mm spot size than with the alexandrite 8 mm spot size, both with or without topical anesthesia. The alexandrite laser was significantly less painful than the diode laser both with and without topical anesthetic. The difference was most noticeable between the alexandrite 8 mm spot size and the diode 9 mm spot size. Topical 5% lidocaine anesthesia was effective in reducing pain, though not completely, for both the alexandrite and the diode lasers.

CONCLUSION

Topical 5% lidocaine cream is a simple and effective method for reducing patient discomfort during laser hair removal procedures, even when a skin cooling device is being used. A larger spot size causes more pain than a smaller spot size at identical fluences. The 800 nm diode laser causes greater discomfort than the 755 nm alexandrite laser.