Laser treatment of pigmented lesions and tattoos

3 Laser treatment of pigmented lesions and tattoos



Kavita Mariwalla, George J. Hruza




Summary and Key Features




• Just as placement of tattoos has gained popularity, so has the number of people interested in their removal


• Black and blue tattoos are the easiest to fade with the most predictable results, whereas multicolored tattoos are the most difficult


• Of the various benign pigmented lesions that can be treated with laser, the easiest to treat are lentigines while the most difficult are the nevi of Ota, Ito, and Hori


• Pigment-specific lasers such as the quality-switched (QS) ruby (694 nm), QS alexandrite (755 nm), and QS Nd : YAG (532 nm and 1064 nm) continue to be the workhorse systems for both tattoo and pigmented lesion removal


• QS lasers remove tattoo pigment through photoacoustic injury, breaking up the ink particles and making them more available for macrophage phagocytosis and removal


• Fractional photothermolysis has provided expanded options for pigmented lesion removal in the last decade, though generally more treatment sessions are required and the cost is higher


• In general, patients with Fitzpatrick skin phototypes I–III have a better response than those with skin phototypes IV–VI as the lasers used for pigment removal can also damage epidermal pigment


• Topical anesthesia is helpful when treating dermal pigmented lesions and tattoos


• Factors to consider prior to estimating the number of treatment sessions a patient will need for tattoo removal include: Fitzpatrick skin phototype, location, color, amount of ink used in the tattoo, scarring or tissue change, and ink layering


• As with any procedure, patient selection and preparation are important to success and photographs of the lesions should be taken prior to each treatment session


• Side effects of laser treatment for pigmented lesions include textural change, scarring, pruritus, hypo- or hyperpigmentation, and immediate pigment change


• Tattoos with white or red ink carry an increased risk of paradoxical darkening after laser treatment, which is why test spots should be carried out prior to the first treatment session


• Caution should be exercised prior to treatment of a tattoo with an allergic reaction as the dispersed ink particles can elicit a systemic response


• For pigmented lesions such as melasma and postinflammatory hyperpigmentation, pre- and postoperative treatment should include hydroquinone and topical retinoids


• Postoperative care includes gentle cleansing and a bland emollient while the skin heals



Introduction


Tattooing has become increasingly popular in recent times, with an estimated 7–20 million people in the USA with at least one. In a 2008 online survey conducted by Harris Interactive, an estimated 14% of all adults in the USA have a tattoo, which corroborates with phone survey results from 2004 in which Laumann & Derick found tattoo prevalence in 26% of males and 22% of females. Interestingly, 17% of those with tattoos considered removal. With advances in laser- and light-based technology, as well as their availability, many patients are not only looking to rid themselves of tattoo ink but also seeking removal of benign pigmented lesions.


In this chapter, we will discuss the use of laser for removing tattoos and ameliorating the appearance of benign pigmented lesions. Although the target for both is pigment, the management of lightening and removal for each condition is distinct.



Pigment removal principles


Quality-switched (‘QS’) lasers have traditionally been the workhorse laser systems for the removal of pigmentation and tattoos. The laser treatment of pigmented lesions is based on the concept of selective photothermolysis; in essence the chosen laser must emit a wavelength that is specific and well absorbed by the intended target. In the case of tattoos, the chromophore is exogenously placed ink found either within macrophages or extracellularly throughout the dermis. In the case of benign pigmented lesions, the intended chromophore is melanin found within melanocytes, keratinocytes or dermal macrophages. Destruction of this pigment is thought to occur mainly through photoacoustic injury. Because the target particles are small, it is important to use pulses of energy that are extremely short to minimize collateral thermal injury to the normal surrounding tissue. For this reason, QS lasers, with energy pulses in the nanosecond range, enable energy to be deposited very quickly. The intense heat transients cause some particles to shatter and kill the cells in which the pigment resides. The rupture of pigment-containing cells eventually triggers phagocytosis and the packaging of pigment fragments for lymphatic drainage and scavenging by dermal macrophages. For epidermal pigment, the pigment-containing cells are killed with the laser pulses resulting in epidermal necrosis and subsequent sloughing and replacement with normal epidermis.


QS lasers used for pigmented lesions include the QS ruby (694 nm), the QS alexandrite (755 nm) and the QS Nd : YAG (532 and 1064 nm) though it is also possible to use the long-pulsed ruby, alexandrite and diode lasers, or intense pulsed light (see Ch. 5). Within the last decade, fractional photothermolysis (‘FP’) has gained popularity for its ability to treat pigmented conditions such as melasma, solar lentigines, nevus of Ota, and postinflammatory hyperpigmentation (see Ch. 6).



Lesion selection


Just as important as patient selection is evaluation of the lesion itself. Tattoos can be divided into amateur, professional, cosmetic, medical, and traumatic categories. In amateur tattoos, a steel needle is used to deposit ink, which may be at various depths of the skin, whereas in professional tattoos, a hollow needle is used to inject ink into the dermal layer of skin. Amateur tattoos typically contain pigment of unknown sources such as ash, coal, or India ink (Fig. 3.1). On the other hand, professional tattoo artists often combine ink pigments to achieve novel colors and shading. Cosmetic tattoos using skin-colored tones are important to distinguish, as are medical tattoos such as those used as radiation markers. For traumatic tattoos, it is important to understand the nature of the injury that caused it so as to be aware of the type of material implanted in the skin prior to treatment.


image

Figure 3.1 Amateur tattoo placed on the hand in a person with Fitzpatrick skin phototype IV.


It is critical when treating pigmented lesions other than tattoos that the lesion itself be evaluated for malignancy. Lasers should not be used for any kind of melanoma, as even with in situ melanoma recurrence rates are very high. Similarly, we recommend against the removal of dysplastic nevi with lasers even though studies have shown no significant increase in carcinogenic markers after laser stimulation of melanocytes.



Patient selection in general


At initial consultation for removal of a pigmented lesion, it is important to take a thorough medical history including a history of allergy to anesthetics (both topical and injectable), current medical conditions, and medications. If a patient is currently taking isotretinoin, laser treatment should be delayed until medication completion as, theoretically, there is a potential for increased scarring and delayed healing. In addition, it is important to note if the patient was ever treated with systemic gold therapy (e.g. rheumatoid arthritis therapy) as this is an absolute contraindication to QS laser treatment since darkening of gold-containing skin is immediate and irreversible. Prophylaxis is appropriate in patients with a history of herpes simplex virus if treating near the trigger point. A history of keloidal scarring and a tendency toward postinflammatory hypo- or hyperpigmentation should also be documented.



Patient selection for tattoo removal


Though tattoos are increasingly popular, they often become a source of personal regret as up to 50% of adults older than 40 with tattoos seek their removal. It is critical that a thorough history of the tattoo be taken prior to deciding upon a treatment plan to establish appropriate patient expectations (Box 3.1). Kirby et al recently published a scale to help practitioners estimate the number of treatment sessions needed for tattoo removal to appropriately guide patients who often enter the laser removal process of their tattoos with uncertainty and misconceptions (Table 3.1). In the scale, numerical values are assigned to six parameters: (1) Fitzpatrick skin phototype, (2) location, (3) color, (4) amount of ink used in the tattoo, (5) scarring or tissue change, and (6) ink layering. The points for each parameter are combined, which results in the approximate number of treatment sessions needed to successfully remove the tattoo, plus or minus 2.5.



Box 3.1


Tattoo lesion patient history




image Is it an amateur, professional, traumatic, cosmetic, or medical tattoo?


image How long has it been present?


image What colors of inks / dyes were used?


image Were inks mixed together to make the colors?


image Is there any white or skin-colored ink in the tattoo to the patient’s knowledge?


image Has the patient attempted to remove or alter the tattoo previously? If so, what technique was used?


image Is the patient currently taking a retinoid?


image Is there a history of herpes infection or cold sores in the proposed treatment area?


image Has the patient previously developed keloids or abnormal scars after prior surgery or injury?


image Does the patient currently actively pursue a tan or use a tanning bed or bronzer?


image What is the patient’s Fitzpatrick skin type?



Table 3.1 Kirby-Desai scale for estimating number of treatment sessions needed for tattoo removal*

image

In addition to setting a realistic number of treatment sessions for the patient, it is important to alert the patient that some tattoo pigment may still remain and that hypopigmentation may occur in the area, which will leave the outline of the tattoo sans ink. This is especially true in patients with Fitzpatrick skin phototypes IV–VI or in patients with a tan.


The ideal patient for tattoo removal is an untanned patient with type I or II skin and a dark-blue or black tattoo that has been present for at least a year. The older the tattoo, the better is the response to laser treatment as macrophages are already present in the skin and have been at work trying to actively phagocytose the foreign pigment particles. This natural attempt by the body to remove the foreign tattoo ink pigment is the reason why older tattoos are often illegible and have blurry or indistinct margins. Multicolored tattoos, regardless of background skin color, can be very difficult to remove completely with traditional laser systems and treatment should be performed only after the patient fully understands the potential for incomplete fading, pigmentary alterations or scarring. Treatment sessions should be spaced at least 6–8 weeks apart.



Patient selection for benign pigmented lesion removal


As with tattoo removal, it is important to assess the patient presenting for benign lesion removal (Box 3.2). The greater the contrast between background skin and pigmented lesion, the more likely the laser surgeon is to achieve success. At preliminary evaluation, a Wood’s lamp examination may be helpful to assess depth of pigment. Understanding whether the lesion is epidermal, present at the dermoepidermal junction, or dermal will guide laser selection and also allow the physician to set realistic expectations for removal.



Box 3.2


Pigmented lesion patient history




image How long has the lesion(s) been present?


image Has a biopsy of the lesion been performed?


image Has it grown, bled without injury, or developed symptoms like itching or changed color?


image Has the patient attempted to remove or alter the lesion previously? If so, how was this attempted?


image Is the patient currently taking an oral retinoid?


image Is there a personal history of herpes infection or cold sores in the proposed treatment area?


image Has the patient previously developed keloids or abnormal scars after prior surgery or injury?


image Does the patient currently actively pursue a tan or use a tanning bed or bronzer?


image What is the patient’s Fitzpatrick skin type?


Patients should not be tanned when treated and it is important to stress that regular sunscreen use will aid in a durable result (especially in the case of solar lentigines). In patients with darker skin types, we recommend pre-treating pigmented areas with hydroquinone 4% and ceasing treatment 1 week prior to laser therapy. Post-therapy we recommend the use of low potency-topical corticosteroids for 3–4 days to prevent any pigment alteration due to inflammation from the treatment itself. Compared with patients with Fitzpatrick skin phototypes I–III, those with skin photoypes IV–VI have a higher risk of pigmentary alteration and scarring.


Lentigines can be treated most reliably, whereas postinflammatory hyperpigmentation (PIH) and nevi of Ota and Ito present more of a challenge.



Patient preparation


The area to be treated should always be free of any topicals. Removal of pigmented lesions and tattoos can be quite painful for the patient, especially if a large area is to be treated. On the face, we recommend topical anesthetic mixtures that can be compounded at the pharmacy consisting of betacaine, lidocaine, and tetracaine (a typical concentration is 7% of each), or the patient can use a commercial preparation such as LMX-4 or EMLA. A thick layer of this mixture is spread evenly over the treatment area with anesthesia taking place usually within 45 minutes. Penetration of the topical anesthetic can be enhanced by putting the medication under occlusion or applying warm towels over the area. Caution should be exercised if the area is large as topical anesthetics can produce toxicity. Anesthetic should always be completely removed prior to treatment.


Ice is another option, though we recommend ice cubes wrapped in frozen gauze rather than ice packs as the latter tend to not maintain an even temperature. The ice should precede the laser treatment with caution to ensure that no water is left behind. For dermal pigmented lesions on the face, such as nevus of Ota, we sometimes will anesthetize the area with 1% lidocaine.


After informed consent is obtained, pre-treatment photographs are taken. As with any medical procedure, universal precautions should be followed. All QS lasers employ a cone or cylinder placed between the handpiece and the skin to catch any skin debris ejected during laser treatment. Because the cones contain fragments of skin, it is important to use gloves when removing them from the laser after treatment.


Eye safety is also paramount when using lasers. Wavelength-specific protective glasses or goggles must be worn by the patient, provider, and staff at all times during a laser procedure. If the area to be treated is on the eyelid or near the orbit, in the case of the deeply penetrating Nd : YAG 1064 nm laser, internal metal eye shields should be placed for the patient.



Pearl 1


Most QS lasers come with a plastic spacer or cone that is attached to the handpiece and touches the skin surface. As a result, the inside of the barrel becomes contaminated with skin debris ejected from the patient’s skin surface. Depending on the device, after treatment, the practitioner has several options. The cone can be either cleaned and sterilized, discarded, or given to the patient to bring to their next treatment. In our experience, patients often forget to bring the cone back, so it is advisable to clean and sterilize the cone after each use.



Pearl 2

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Apr 2, 2016 | Posted by in Laser surgery | Comments Off on Laser treatment of pigmented lesions and tattoos

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