Hair Regrowth Treatment Botulinum Toxin A Face lift / Neck lift Body Reshaping / Contouring Hair Fall / Loss Treatment Laser Hair Reduction
Dr Ravindra Dargainya

Dr. Ravindra Dargainya

Dermatologist, Cosmetologist, Trichologist, Allergy Specialist, STI/AIDS Consultant

Dr Prachi Dargainya

Dr. Prachi Dargainya

Physiotherapist & Nutritionist

Skilled in Orthopaedic injuries, Aches and Pain, Bell's Palsy, Paralysis, Ante/Post natal Consultation.

Tattoo removal

Tattoo removal has been performed with various tools during the history of tattooing. While tattoos were once considered permanent, it is now possible to remove them with treatments, fully or partially.

Before the development of laser tattoo removal methods, commons techniques included dermabrasion, TCA (Trichloroacetic acid, an acid that removes the top layers of skin, reaching as deep as the layer in which the tattoo ink resides), salabrasion (scrubbing the skin with salt), cryosurgery and excision which is sometimes still used along with skin grafts for larger tattoos. Some early forms of tattoo removal included the injection or application of wine, lime, garlic or pigeon excrement. Tattoo removal by laser was performed with continuous-wave lasers initially, and later with Q-switched lasers, which became commercially available in the early 1990s. Today, "laser tattoo removal" usually refers to the non-invasive removal of tattoo pigments using Q-switched lasers. Typically, black and darker-colored inks can be removed more completely.

Methods

Tattoo removal is most commonly performed using lasers that break down the ink particles in the tattoo. The broken-down ink is then absorbed by the body, mimicking the natural fading that time or sun exposure would create. All tattoo pigments have specific light absorption spectra. A tattoo laser must be capable of emitting adequate energy within the given absorption spectrum of the pigment to provide an effective treatment. Certain tattoo pigments, such as yellows, greens and fluorescent inks are more challenging to treat than darker blacks and blues, because they have absorption spectra that fall outside or on the edge of the emission spectra available in the tattoo removal laser. Recent pastel coloured inks contain high concentrations of titanium dioxide which is highly reflective. Consequently, such inks are difficult to remove since they reflect a significant amount of the incident light energy out of the skin.

Widely considered the gold standard treatment modality to remove a tattoo, laser tattoo removal requires repeat visits.

The energy density (fluence), expressed as joules/cm2, is determined prior to each treatment as well as the spot size and repetition rate (hertz). During the treatment process the laser beam passes harmlessly through the skin, targeting only the ink resting in a liquid state within. While it is possible to see immediate results, in most cases the fading occurs gradually over the 7–8 week healing period between treatments.

Mechanism of laser action

Tattoos consist of thousands of particles of tattoo pigment suspended in the skin. While normal human growth and healing processes will remove small foreign particles from the skin, tattoo pigment particles are permanent because they are too big to be removed. Laser treatment causes tattoo pigment particles to heat up and fragment into smaller pieces. These smaller pieces are then removed by normal body processes.

Laser tattoo removal is a successful application of the theory of selective photothermolysis (SPTL).However, unlike treatments for blood vessels or hair the mechanism required to shatter tattoo particles uses the photomechanical effect. In this situation the energy is absorbed by the ink particles in a very short time, typically nanoseconds. The surface temperature of the ink particles can rise to thousands of degrees but this energy profile rapidly collapses into a shock wave. This shock wave then propagates throughout the local tissue (the dermis) causing brittle structures to fragment. Hence tissues are largely unaffected since they simply vibrate as the shock wave passes. For laser tattoo removal the selective destruction of tattoo pigments depends on four factors:

  • The color of the light must penetrate sufficiently deep into the skin to reach the tattoo pigment.
  • The color of the laser light must be more highly absorbed by the tattoo pigment than the surrounding skin. Different tattoo pigments therefore require different laser colors. For example, red light is highly absorbed by green tattoo pigments.
  • The time duration (pulse duration) of the laser energy must be very short, so that the tattoo pigment is heated to fragmentation temperature before its heat can dissipate to the surrounding skin. Otherwise, heating of the surrounding tissue can cause burns or scars. For laser tattoo removal, this duration should be on the order of nanoseconds.
  • Q-switched lasers are the only commercially available devices that can meet these requirements.

    Although they occur infrequently, mucosal tattoos can be successfully treated with Q-switched lasers as well.

    Number of laser tattoo removal treatment sessions needed

    Complete laser tattoo removal requires numerous treatment sessions. At each session, some but not all of the tattoo pigment particles are effectively fragmented, and the body removes the smallest fragments over the course of several weeks. The result is that the tattoo is lightened over time. Remaining large particles of tattoo pigment are then targeted at subsequent treatment sessions, causing further lightening. The number of sessions and spacing between treatments depends on various parameters, including the area of the body treated and skin color. Tattoos located on the extremities, such as the ankle, generally take longest. As tattoos fade clinicians may recommend that patients wait many months between treatments to facilitate ink resolution and minimize unwanted side effects.

    The amount of time required for the removal of a tattoo and the success of the removal varies with each individual. Factors influencing this include: skin type, location, color, amount of ink, scarring or tissue change, and layering.

    Factors contributing to the success of laser tattoo removal

    Multiple factors contribute to the success of laser tattoo removal, one of which is a patient's own immune system. Moreover, treatment on some patients with immune systems problems are contraindicated.

    Pain management during treatment

    Laser tattoo removal is uncomfortable - many patients say it is worse than getting the tattoo on. The pain is often described to be similar to that of hot oil on the skin, or a "snap" from an elastic band. Depending on the patient's pain threshold, and while some patients may forgo anesthesia altogether, most patients will require some form of local anesthesia. Pre-treatment might include the application of an anesthetic cream under occlusion for 45 to 90 minutes prior to the laser treatment session. A better method is complete anesthesia which can be administered locally by injections of 1% to 2% lidocaine with epinephrine.

    Post-treatment considerations

    Immediately after laser treatment, a slightly elevated, white discoloration with or without the presence of punctuate bleeding is often observed. This white color change is thought to be the result of rapid, heat-formed steam or gas, causing dermal and epidermal vacuolization. Pinpoint bleeding represents vascular injury from photoacoustic waves created by the laser's interaction with tattoo pigment. Minimal edema and erythema of adjacent normal skin usually resolve within 24 hours. Subsequently, a crust appears over the entire tattoo, which sloughs off at approximately 14 days post-treatment. As noted above, some tattoo pigment may be found within this crust. Post-operative wound care consists of simple wound care and a non-occlusive dressing. Since the application of laser light is sterile there is no need for topical antibiotics. Moreover, topical antibiotic ointments can cause allergic reactions and should be avoided. Fading of the tattoo will be noted over the next eight weeks and re-treatment energy levels can be tailored depending on the clinical response observed.

    Side effects and complications

    About half of the patients treated with Q-switched lasers for tattoo removal will show some transient changes in the normal skin pigmentation. These changes usually resolve in 6 to 12 months.

    Hyperpigmentation is related to the patient's skin tone, with skin types IV, V and VI more prone regardless of the wavelength used. Twice daily treatment with hydroquinones and broad-spectrum sunscreens usually resolves the hyperpigmentation within a few months, although, in some patients, resolution can be prolonged.

    Transient textural changes are occasionally noted but often resolve within a few months; however, permanent textural changes and scarring very rarely occur. If a patient is prone to pigmentary or textural changes, longer treatment intervals are recommended. Additionally, if a blister or crust forms following treatment, it is imperative that the patient does not manipulate this secondary skin change. Early removal of a blister of crust increases the chances of developing a scar. Additionally, patients with a history of hypertrophic or keloidal scarring need to be warned of their increased risk of scarring.

    Local allergic responses to many tattoo pigments have been reported, and allergic reactions to tattoo pigment after Q-switched laser treatment are also possible. Rarely, when yellow cadmium sulfide is used to "brighten" the red or yellow portion of a tattoo, a photoallergic reaction may occur. The reaction is also common with red ink, which may contain cinnabar (mercuric sulphide). Erythema, pruritus, and even inflamed nodules, verrucose papules, or granulomas may present. The reaction will be confined to the site of the red/yellow ink. Treatment consists of strict sunlight avoidance, sunscreen, interlesional steroid injections, or in some cases, surgical removal. Unlike the destructive modalities described, Q-switched lasers mobilize the ink and may generate a systemic allergic response. Oral antihistamines and anti-inflammatory steroids have been used to treat allergic reactions to tattoo ink.

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