Experimental Nonsurgical Tattoo Removal in a Guinea Pig Model with Topical Imiquimod and Tretinoin

BACKGROUND: Tattoo removal is a common request in dermatologic surgery practices. Conventional tattoo removal modalities consist of mechanical, chemical, and thermal methods, but these interventions may result in undesirable dermal damage, disfiguring scars, and pigmentary changes. OBJECTIVE: To evaluate the efficacy of topical imiquimod and tretinoin for the removal of tattoos in a guinea pig model. METHODS: Five albino guinea pigs (A-E) were tattooed with black, red, green, and yellow. Beginning 6 hours after tattooing, A received no treatment, B was treated with petrolatum, C had imiquimod cream alternating with tretinoin gel, D had imiquimod cream alone, and E received tretinoin gel alone. The animals were treated for 7 days. Biopsies of the tattoos were taken at 6 hours, 7 days, and 28 days. RESULTS: Control guinea pig B had normal-appearing tattoos with consistent histopathology on day 28. Guinea pig D, treated with imiquimod cream clinically, had no visible tattoo, consistent with greatly diminished or no dye evident on histopathology. Guinea pig E, treated with tretinoin gel, and guinea pig C, treated with combination tretinoin gel and imiquimod cream, had faded tattoos and moderate clearance of pigment on histopathology. CONCLUSION: In the guinea pig, the use of imiquimod was successful as a nonsurgical method of acute-phase tattoo removal, but was associated with fibrosis and the loss of dermal appendages.     

Topical imiquimod in conjunction with Nd:YAG laser for tattoo removal

The purpose of this study is to evaluate the efficacy of tattoo removal using topical imiquimod 5% cream in conjunction with the 1,064-nm Nd:YAG laser. This procedure for tattoo removal will be compared to laser treatment alone, which is the standard for cosmetic removal of tattoos. Previous studies have linked partial tattoo removal to imiquimod application in a guinea pig model. Methods: This was a small-sized, double-blinded, placebo-controlled trial with patients with Fitzpatrick skin types I-IV (light skin) who were 18–65 years of age. The patients were required to have had two tattoos of similar age and dark blue or black in color in areas that can be covered by clothing. There were four visits in total, with laser treatment and photography being performed on the first visit. Laser settings were with 1,064-nm Nd:YAG with a 10-ns pulse, 3-mm spot size, and 4 J of energy, a standard laser used for tattoo removal. During the second visit, tattoos were randomized and chosen to receive either the laser-imiquimod treatment course or laser-vehicle cream treatment. The patients returned 1 month after the completion of cream application (week #10) and 2 months after the completion of treatment with cream (week #14) for final evaluation and photographing. Results: Three patients were enrolled in this study. All of them are Fitzpatrick skin type IV. All of the patients were compliant with the drug application and have good tolerability with only mild pruritus without changing of vascularity or pigmentation. None of the patients had ulceration or scar development during the cream application. Conclusions: imiquimod plus laser therapy demonstrated a more favorable outcome when evaluated by the investigators or subjects. The mean scores for tattoo clearance from baseline to 2 months after completion of treatment with 5% imiquimod cream versus placebo cream were 4.3 versus 2.7 as rated by investigators and 4.7 versus 2.3 as rated by subjects. No textural changes were observed after therapy and were not shown to be different between the two groups. Further large-scale studies are important in developing a role for the use of imiqumod in laser-assisted tattoo removal.     

Laser-Assisted Tattoo Removal with Topical 5% Imiquimod Cream

BACKGROUND: Laser-assisted tattoo removal is effective but can be costly and time-consuming and can result in disfiguring scars and pigment alterations. Imiquimod, an immune response modifier, may play a role in tattoo removal. OBJECTIVE: The objective was to evaluate the safety and efficacy of topical 5% imiquimod cream used daily in conjunction with laser therapy to remove unwanted tattoos. MATERIALS AND METHODS: Twenty subjects with two similar tattoos were enrolled in this randomized, prospective, double-blinded, case-controlled study. Tattoos were treated with either imiquimod or placebo daily and laser therapy every 4 to 6 weeks for a total of six sessions. The primary efficacy parameter was tattoo clearance (5-point scale, poor through complete). Secondary efficacy parameters included textural changes (5-point scale, minimal through severe), pain during and between laser procedures, and undesirable pigment alterations. RESULTS: Nineteen subjects completed the study. The mean score for tattoo clearance with imiquimod versus placebo was 3.2 versus 2.9 and, for textural changes, was 1.37 versus 1.21 (differences not statistically significant). There was no difference in subjective pain during and between laser sessions and no undesirable pigment alterations were reported. Adverse reactions were more frequent with imiquimod compared to placebo. CONCLUSION: Topical imiquimod is an ineffective adjunct to laser-assisted tattoo removal.     

Role of the alexandrite laser for removal of tattoos

Background and Objective: The development of the Alexandrite laser for the removal of blue-black tattoos is described. Study Design/Materials and Methods: The responses of an animal study, using professionally tattooed skin and a human study involving 22 (professional and nonprofessional) blue-black tattoos, to the Alexandrite laser are reported. Results: Histopathologic evaluation of tattooed pig skin biopsies demonstrated the method of removal of dermal tattoo pigment. An average 11.6 treatments were required to remove completely the ten human blue-black professional tattoos compared to an average of 10.3 treatments to reach the same endpoint in six subjects with nonprofessional tattoos. Conclusion: Of significance was the fact that unlike the Q-switched Ruby and Nd: YAG lasers where punctate bleeding and tissue splattering have been reported to occur during laser tattoo removal, epidermal integrity was maintained during exposure of tattooed skin to the Q-switched Alexandrite laser at therapeutic fluences used. © 1995 Wiley-Liss, Inc.     

Laser ablation of facial cosmetic tattoos

The application of facial cosmetic tattoos (eyeliner, lipliner, and rouge) has become popular over the past five years and has resulted in an increasing number of patients requesting removal of these permanent cosmetics. Poor positioning or misapplication of the tattoo pigment has been the most common reason for requesting removal. Because of the almost inevitable probability of scarring, removal of these facial tattoos has been difficult at best. We report the successful removal of facial cosmetic tattoos in ten different patients with the use of five different lasers. We have found the superpulsed C0₂ laser and the Q-switched alexandrite laser to be effective in removal of black tattoo pigment. The alexandrite laser is effective without causing scarring, and the C0₂ laser is extremely precise and provides the capability of removing tattoo pigment between eyelash or eyebrow hairs without damaging the hair follicles. Both the argon laser and the flashlamp pumped dye laser reacted with red tattoo pigment and offered some improvement but were not ideally suited for tattoo removal. However, the flashlamp pumped dye laser for pigment was very effective in removing red tattoo pigment possibly because of its short pulse width (300 ns) in addition to its appropriate wavelength. The combination of these three lasers (superpulsed CO₂, alexandrite, and flashlamp pigment lasers) is very effective in removing black and red (or shades thereof) facial tattoos. Caution must be taken to determine the presence of flesh-colored tattoo pigment, as this pigment (FE₂O₃) will reduce to black (FeO) upon laser impact.     

Treatment of an Amalgam Tattoo with a Q-Switched Alexandrite (755 nm) Laser

BACKGROUND: Amalgam tattoos result from deposition of metallic particles (eg, silver, mercury, copper, zinc, and tin) into the oral mucosa. Their clinical and histologic appearance is similar to that of decorative tattoos. OBJECTIVE: To describe the successful use of a Q-switched alexandrite laser for removal of an amalgam tattoo. MATERIALS AND METHODS: An amalgam tattoo on the buccal mucosa and gingiva was treated with a QS 755 nm alexandrite laser. Three treatments were delivered at 8-week time intervals (average fluence = 6.8 J/cm2). RESULTS: Significant lightening of the tattoo was achieved after each of the three treatments without adverse sequelae. CONCLUSION: Q-switched alexandrite laser irradiation can safely and effectively eradicate amalgam tattoos.     

The Kirby-Desai Scale: A Proposed Scale to Assess Tattoo-removal Treatments

Background: As tattoos have become increasingly popular in the Western world, tattoo-removal requests have also increased, as patients’ personal identities advance. Laser tattoo removal is the current treatment of choice given its safety and efficacy. However, due to varying types of tattoos, it has been difficult to quantify the number of laser treatments required with certainty when discussing laser tattoo removal with our patients. Objective: To propose a practical numerical scale to assess the number of laser tattoo-removal treatments necessary to achieve satisfactory results. Methods and materials: A retrospective chart review was performed on 100 clinic patients who presented for laser tattoo removal. An algorithm was proposed to assign a numerical score to each tattoo across six different categories (skin type, location, color, amount of ink, scarring, and layering). The cumulative score (Kirby-Desai score) is proposed to correlate with the number of treatment sessions required for satisfactory tattoo removal. Results: A correlation coefficient of 0.757 was achieved, with satisfactory tattoo removal in all subjects (N=100, p<0.001). Conclusion: We propose the Kirby-Desai scale as a practical tool to assess the number of laser tattoo-removal sessions required, which will translate into a more certain cost calculation for the patient.The art of tattooing has a long-dated history in civilization with origins dating back to 12,000 BC.¹ From ancient times to modern day, tattoos have gained increasing popularity among many demographic populations with current estimates of more than 20 million people (3–5% of the population) having at least one tattoo.^2,3 However, tattoos often become a personal regret, as up to 50 percent of adults older than 40 seek tattoo removal as a means to fix their tattoo quest.⁴ Lasers have been used to remove tattoos since the late 1970s and have in recent years become the mainstay for removal due to their high efficacy and low incidence of deleterious side effects. Although a patient’s decision to remove a tattoo is definitive, the logistical uncertainty remains—such as the number of treatments and whether laser tattoo removal will be successful—adding unwanted burdens on the patient.In this paper, we propose the Kirby-Desai scale to assess the potential success and number of treatments necessary for laser tattoo removal, assuming the medical practitioner is using a quality-switched Nd:YAG (neodymium-doped yttrium aluminum garnet) or Alexandrite laser incorporating selective photothermolysis with 6 to 8 weeks between treatments. This scale can be used by the physician during preconsultation to determine the number of treatments required for tattoo removal, decreasing the uncertainty of the laser-removal process. Currently, patients receive a poorly defined assessment of the number of treatments and often engage in the process without full awareness of the potential success. In the Kirby-Desai scale, numerical values are assigned to six parameters: skin type, location, color, amount of ink, scarring or tissue change, and layering. Parameter scores are then added to yield a combined score that will show the estimated number of treatments needed for successful tattoo removal. Tattoos scoring greater than 15 points may be difficult to remove and should be assessed by the physician to decide whether laser removal is the method of choice for the patient. The Kirby-Desai scale is the first proposed scale, to our knowledge, that enables physicians to have a thorough laser-removal assessment and hopefully aids in defining a more accurate treatment plan and improve patient satisfaction.     

Picosecond lasers for tattoo removal: a systematic review

Given that the pigment particles in tattoos have a relaxation time of <10 ns, picosecond lasers would be expected to be more effective than nanosecond lasers in tattoo removal. To systematically review the evidence regarding the effectiveness and safety of picosecond lasers for tattoo removal, Pubmed, Cochrane Central Register of Controlled Trials (CENTRAL), ClinicalTrials.gov, and reference lists were searched for relevant trials. The primary outcome was >70 % clearance of tattoo pigment. Secondary outcomes were 90–100 % clearance of tattoo pigment, number of laser sessions required, and adverse effects. Eight trials were included, six with human participants (160 participants) and 2 with animal models. Seven of the eight trials explored the usage of either 755, 758, 795, 1064, or 1064/532-nm picosecond lasers for black and blue ink tattoos. In the human trials, 69–100 % of tattoos showed over 70 % clearance of pigment after 1–10 laser treatments. Reported side effects included pain, hyperpigmentation and hypopigmentation, blister formation and transient erythema, edema, and pinpoint bleeding. Included articles varied in type of laser investigated, mostly non-comparative studies and with a medium to high risk of bias. There is sparse evidence that picosecond lasers are more effective than their nanosecond counterparts for mainly black and blue ink tattoo removal, with minor side effects.     

Temporary dermal scatter reduction: quantitative assessment and implications for improved laser tattoo removal

BACKGROUND AND OBJECTIVES: Temporary dermal clearing, i.e., reduction in the attenuation coefficient of the dermis and epidermis, may lead to improved laser tattoo removal by providing increased efficiency of laser delivery to embedded ink particles and enabling the use of shorter wavelength visible lasers more effective on certain inks. STUDY DESIGNS/MATERIALS AND METHODS: In a hairless guinea pig model of human tattoo, we tested both intradermal and transdermal application of glycerol, using visual inspection, spectral analysis, and optical coherence tomography techniques to assess effectiveness. In controlled experiments, we compared the outcomes of single laser treatment sessions for both cleared and uncleared tattoo sites using Q-switched 755 and 532 nm lasers on three different inks. RESULTS: Intradermal injection of clearing agents induced dermal clearing but resulted in necrosis and scar. Transdermal application of clearing agents resulted in moderate reversible clearing, which was localized to the superficial layers of the skin and did not result in complications. Statistically significant differences in laser treatment outcome were observed relative to a number of treatment parameters including the treatment of certain tattoos by short wavelength lasers. CONCLUSIONS: Temporary clearing of superficial skin layers may be performed in an apparently safe and reliable manner. Clearing should lead to increased penetration of laser light to tattoos and should, therefore, increase treatment efficiency. Further study is needed to determine the degree to which this change is of clinical value.     

Transient immunoreactivity after laser tattoo removal: report of two cases

BACKGROUND AND OBJECTIVE: Laser tattoo removal is one of most commonly used indications for medical lasers. Professional tattoos contain a multitude of potentially immunogenic chemicals that are released or modified by laser treatment. We studied potential immunologic reactions following laser tattoo removal. STUDY DESIGN/PATIENTS AND METHODS: Case report of two patients with immunologic reactions after laser tattoo removal. RESULTS: Two patients developed transient immunoreactivity that presented as regional lymphadenopathy after laser tattoo removal of professional black and blue-green tattoos. These reactions resolved without any complications. CONCLUSIONS: Tattoo pigments released or modified by laser therapy may trigger transient immunoreactivity in susceptible individuals.     

Use of Onion Extract, Heparin, Allantoin Gel in Prevention of Scarring in Chinese Patients Having Laser Removal of Tattoos: A Prospective Randomized Controlled Trial

BACKGROUND: With rapid advancement in cutaneous laser therapy, Q-switched lasers have become the standard treatment for tattoo removal. The longer wavelength Q-switched Nd:YAG laser is used when removing tattoos in darker skin patients to avoid scarring and permanent pigment changes. Nevertheless, the local experience revealed that nearly 25% of the Chinese patients developed scarring. Meanwhile, multiple clinical studies have shown that Contractubex gel (Merz Pharma, Frankfurt, Germany) was effective in the treatment and prevention of hypertrophic scars and keloids. OBJECTIVE: To evaluate the efficacy of Contractubex gel in the prevention of scarring after laser removal of tattoos in Chinese patients. METHODS: A total of 120 Chinese patients with 144 professional blue-black tattoos were recruited into the study. They were randomly assigned into the Contractubex group or the control group. All patients were treated with a QS 1,064-nm Nd:YAG laser using a 3-mm spot size, a 10-Hz repeat rate, a pulse duration of 6 nanoseconds, and fluences that ranged from 3.6 to 4.8 J/cm2 (mean fluence, 4.2 J/cm2). The treated areas were assessed 3 months after the last treatments for clinical clearance and complications. RESULTS: Fifty-two patients with 61 tattoos in the Contractubex group were able to achieve a mean clearing rate of 82.3+/-11.6%. There were 7 tattoos in 7 patients that developed scarring, 4 patients had permanent hypopigmentation, and 3 patients had transient hyperpigmentation. In contrast, 55 patients with 68 tattoos in the control group had a mean clearing rate of 80.4+/-11.3%. Among them, 16 tattoos in 14 patients developed scarring, 4 patients had permanent hypopigmentation, and 5 patients had transient hyperpigmentation. Although there was no significant difference in age, sex, fluence, treatment session, and clinical clearance between the two groups, the Contractubex group had a statistically significantly lower rate of scarring than the control group (p<.05). CONCLUSION: Contractubex gel is effective in scar prevention in Chinese patients having laser removal of tattoos.     

In vivo study of intradermal focusing for tattoo removal

. Delivery of intradermally focused nanosecond laser pulses with small energy as an alternate technique applicable to clinical procedures in dermatological and plastic surgery is an area of relatively new interest with multiple potential applications. We assessed this approach on common tattoo pigments in dermis in an in vivo study using a wavelength of 1064 nm. Paired micropigs were tattooed with standard blue, black, green and red pigments. The tattoos were allowed to mature and then treated by 12 ns pulses in a focused beam of 11.4° cone angle. Visual observation and histological analysis of biopsies were performed to evaluate results. Significant reduction in pulse energy and collateral damage was achieved with pulse energy ranging between 38 to 63 mJ. Blue and black tattoos were found to respond well from a clinical standpoint. The depth dependence of tissue response and pigment redistributions at 1 hour, 1 week and 1 month after laser treatment was quantitatively analysed through biopsies and a strong relationship was demonstrated between tattoo response and laser-induced dermal vacuolation. The optical absorption coefficients of the four tattoo pigments were measured to be approximately the same and the laser-induced plasma is suggested to be responsible for the pigment redistribution. As we hypothesised, intradermal focusing of nanosecond pulses significantly reduced required pulse energy for tattoo ablation to about 60 mJ or less. These results stimulate a number of additional questions relevant not only to clinical applications but also to the understanding of the fundamental process of laser–pigment interaction in the dermis as it relates to tattoo removal. Paper received 1 November 2001; accepted after revision 14 December 2001     

Colour shift following tattoo removal with Q-switched Nd-YAG laser (1064/532).

Colour shift in tattoo pigment is a recognised complication of laser tattoo treatment. We report our experience over the past 4 years in treating 275 patients, with a total of 323 professional tattoos. Of these, 184 tattoos contained a pigment other than black with 33 displaying a colour shift as a consequence of laser treatment. This adverse effect was recorded with red, yellow, crimson and brown pigments but most frequently with white/flesh pigments. We found brown and white/flesh coloured pigments to be significantly more likely to change colour compared to red and that the chance of certain colours shifting related to the age of the tattoo. We outline our management of this problem and discuss the results of continued treatment.     

Traumatic tattoo removal: comparison of four treatment methods in an animal model with correlation to clinical experience

The acute or emergency treatment of traumatic tattoos has been based on the principles of immediate and thorough removal of all particles. The delayed treatment of traumatic tattoos has classically been with overgrafting or dermabrasion. We developed an animal model for traumatic tattoos. Two levels of wounds were made (shallow and deep). Each group consisted of five guinea pigs with one consistent level of wounding. Four treatment methods were applied: carbon dioxide laser, argon laser, overgrafting, and dermabrasion. The results were evaluated by trained observers on a gross basis. Although no statistically significant differences were found within these small groups, clinical experience in a small group of patients suggests that carbon dioxide laser may prove to be useful in the delayed treatment of traumatic tattoos. Eight patients have been treated over a 4-year period. Satisfactory total or subtotal foreign body removal of various agents (road tar, cement, cooper particles) has been achieved.     

Multiple Color Changes Following Laser Therapy of Cosmetic Tattoos

OBJECTIVE: To emphasize the wisdom of small test areas when treating cosmetic tattoos and the need for multiple laser systems. METHODS: A 48-year-old woman requested removal of permanent makeup (cosmetic tattoos) of her eyebrows and around her lips. Physical examination revealed a brown tattoo of both eyebrows and dark red lip liner around both lips. A test area was performed on the red tattoo of the lips. A frequency-doubled Nd:YAG laser (532 nm, 2.0 J/cm2, 2 mm spot size) was used for the lip area, while the same laser at 1064 nm, 3.9 J cm2, 2 mm spot size was utilized for the eyebrows. The lip area immediately turned black. The patient returned for follow-up 1 month later; the black ink on the lip was treated with the same laser at 1064 nm, 3 mm spot size, 4.2 J/cm2, with satisfactory resolution in two monthly treatments. Both brown eyebrow turned bright orange and were treated with 532 nm, 3 mm, 3.0 J/cm2. One month later the eyebrows were a mixture of yellow ink and dark green. The yellow area was treated with 532 nm, 3 mm, 2.3 J/cm2, while the dark green was treated with the 1064 nm, 3 mm spot size, 4.2 J/cm2. One month later little improvement was noted, so Q-switched ruby laser at 694 nm, 6 mm spot size, 16 J/cm2 was utilized. An additional four monthly treatments were given utilizing a combination of both ruby and 532 nm ND:YAG lasers for green and yellow pigment, respectively. RESULTS: Significant but incomplete resolution of the tattoo ink was achieved. CONCLUSION: Multiple laser systems are needed to remove cosmetic tattoos. Test areas must be done before treatment.     

Magnetite tattoos

BACKGROUND AND OBJECTIVES: Tattoo removal is a significant problem. The extraction of magnetite (Fe(3)O(4)) ink tattoos by a magnetic field was investigated, with and without Q-switched laser treatment. STUDY DESIGN/MATERIALS AND METHODS: Magnetite particles (1.4 microm) were used to make mature, black skin tattoos on hairless albino rats. A Q-switched ruby laser (QSRL) 3.5 J/cm(2), 6.5-mm spot size, 40-nanosecond pulse width was used for treatment. Permanent magnets (1.4 T, 6-mm diameter) were tested to extract the magnetite particles, alone and after QSRL. Lightening of treated tattoos was measured from digital photographs, and the amount and distribution of magnetite in skin biopsies was scored blindly. RESULTS: External application of magnets on mature magnetite tattoos without prior QSRL treatment, did not significantly extract, lighten, darken, or change their histologic appearance. A magnetic field applied immediately after QSRL treatment extracted some ink when epidermal injury was present, and caused significant redistribution of magnetite into the upper dermis with vertical banding along magnetic field lines. When applied for 3 weeks following QSRL, magnets caused darkening of tattoos. CONCLUSIONS: Magnetite skin tattoos can be manipulated by external magnets, especially after Q-switched laser treatment. Magnetically-extractable tattoos may be feasible.     

Treatment of Gunpowder Traumatic Tattoo by Q-Switched Nd:YAG Laser: An Unusual Adverse Effect

BACKGROUND: The Q-switched Nd:YAG laser can completely eliminate traumatic tattoos. OBJECTIVE: We report the results of the unsuccessful removal of traumatic tattoos among three patients with dermal inclusions of gunpowder who were shot at close range. METHODS: Treatment was tried in each patient with a Q-switched Nd:YAG laser at a medium fluence (4-6 J/cm2). RESULTS: During treatment of our patients, each pulse provoked sparks and the immediate formation of bleeding trans- epidermal pits. After the healing process was completed, we observed poxlike scars and the spreading of pigments in the skin around the initial points of the tattoo. CONCLUSION: We hypothesize that the rapid transfer of high-energy pulses to powder particles creates microexplosions of these fragments resulting in cavitation and provoking transepidermal holes and subsequent scars. This adverse effect was only produced if the tattoo resulted from gun powder being shot at a short distance from the skin.     

Successful treatment of treatment-resistant laser-induced pigment darkening of a cosmetic tattoo

BACKGROUND AND OBJECTIVE: Cosmetic tattoo removal has a reported risk of immediate pigment darkening when treated with a high energy, nanosecond pulsed-laser system. Surgical treatment options for this reaction are limited and carry significant risk of scarring and permanent pigment alterations. This report describes the response of a resistant Q-switched ruby laser-induced cosmetic tattoo ink darkening to multiple treatments with the Q-switched alexandrite laser and Q-switch Nd:YAG laser and textural improvement with the UltraPulse CO(2) laser. STUDY DESIGN/MATERIALS AND METHODS: A woman with Q-switched ruby laser-induced pigment darkening of a cosmetic tattoo of the upper lip resistant to four further treatments with the ruby laser and two chemical peels received a total of 26 treatments with the Q-switched alexandrite and Nd:YAG lasers and a single treatment with the UltraPulse CO(2) laser, most treatments being done at monthly intervals. RESULTS: Treatment of the affected areas with the Q-switched alexandrite and Nd:YAG lasers resulted in complete clearing of the pigment without scarring, but revealed some preexisting textural changes. Use of the UltraPulse CO(2) laser smoothed the surface irregularities. CONCLUSION: The Q-switched pigment lasers are a useful modality for treating this pigment darkening reaction. As in this case, multiple treatment sessions with the laser may be necessary but the pigment can be expected to clear eventually without scarring. Any textural changes may be blended with the UltraPulse CO(2) laser with further improvement.     

Q-switched laser treatment of tattoos

In the last decade, Q-switched lasers have expanded the clinician’s ability to treat decorative, cosmetic and traumatic tattoos without scarring. Previous methods of gross tissue removal with resultant scarring have been replaced by the highly selective removal of tattoo pigment with minimal changes in skin texture or pigmentation. This article reviews use of the Q-switched ruby, Q-switched neodymium-yttrium-aluminum-garnet and Q-switched alexandrite lasers in the clinical management of patients with tattoos.     

Q-switch laser and tattoo pigments: first results of the chemical and photophysical analysis of 41 compounds

BACKGROUND AND OBJECTIVE: In the Western world, there are at least 20-30 million people with tattoos. Improved self-image and social stigmatization are the main reasons for removing tattoos from skin. Q-switched lasers are applied to destroy the tattoo compounds in the skin. The treatment of tattoos containing ink often gives excellent results, whereas the results of treatments for coloured tattoos are not predictable and usually are worse. The chemical structure and the absorption spectra of the tattoo pigments are usually unknown. However, the efficacy of the treatment by using light of different Q-switched lasers (wavelengths 510, 532, 694, 755, 1064 nm) is correlated to both the chemical structure of the tattooed compounds yielding specific absorption spectra and the laser wavelength used. STUDY DESIGN/MATERIALS AND METHODS: A structural and spectroscopic analysis of 41 coloured pigments was performed. RESULTS: The 41 substances were identified, and they consist of 16 individual chemicals of different structured well-known industrial organic pigments. The absorption spectra of the 16 pigments were measured quantitatively. CONCLUSION: The results of the present analysis explain to some extent the outcome of clinical studies regarding laser therapy of coloured tattoos. Because the laser energy used produces a high temperature in the azo or polycyclic pigments, it is necessary to investigate whether that change causes possibly toxic or cancerogenic compounds.