Overview of Skin
There are three main layers to the skin: the epidermis, dermis, and subcutaneous layer.
Epidermis – the outermost layer serves as the first layer of defense against the outside world. Cells at the surface are dead, and they fall off and away as upward pressure is applied by continuously multiplying cells in the lower epidermis
Dermis – provides the skin’s structural integrity, elasticity, and resilience; includes fibroblasts, capillaries, lymph nodes, sweat glands, hair glands, but only a few nerves and muscle cells
Our skin contains three major chromophores that absorb the wavelengths of light that are used in laser tattoo removal.
Melanin: gives skin its tone or color. Darker skin has more melanin. Patients with darker skin types (Types IV-VI) may experience some destruction of melanin when the 1064nm light is absorbed, but it will re-generate by itself.
Hemoglobin (blood): absorption of energy especially by 532nm may lead to purpura (redness, bruising)
H20 (water): absorption low for 532nm, very moderate absorption for 1064nm
Previous laser used for tattoo removal (inc. CO2 lasers operated at a wavelength that led to massive absorption of energy by H20 and vaporization (and scarring) of the skin.
How q-switched lasers interact with tissue
When energy absorbed by tattoo pigment or shattered by photo-acoustic effect, there is a fragmentation of ink particles to 10x to 100x smaller.
Laser-induced optical property changes: particles change from clear to black.
Release of pigment particles into the extracellular dermal space.
Partially elimination of ink in a scab form but greater elimination into the lymphatic system.
Laser Light and the Skin
When laser light reaches the stratus corneum and epidermis, a number of paths are available to the light. Some reflects off from the outmost layer of skin; other penetrates into the epidermis and dermis and then is reflected. One technique used in all laser treatments is to hold the laser handpiece is such a way that minimizes this wasted energy lost to reflectance.
Other laser energy penetrates into the epidermis and dermis and reaches chromophores such as tattoo ink particles and is absorbed. It is this absorption that excites the particles leading to a rapid increase in temperature and the shattering of tattoo ink.
Phagocytes are cells found in the blood, bone marrow, and other tissue that ingest pathogenic and infectious agents in the body.
Phagocyte comes from the Greek word phagein, meaning to eat or devour
Many sub-categories (inc. neutrophils seen in the picture to the right devouring anthrax) that perform different tasks but in general these helper cells will help to flush away shattered tattoo particles.
Stimulating phagocytes may be possible with powerful immune-modifying topical drugs such as Imiquimod, but with potentially serious side effects that make it a poor choice for a cosmetic procedure such as laser tattoo removal.
Skin Types and Tattoo Removal
Skin type matters because darker skin (Types IV or higher) may be more likely to experience hypo pigmentation or keloid scarring.
These patients will want to start with lower fluence (energy) levels than other patients with subsequent evaluation to see how skin reacts to treatment.
Hypo pigmentation with few exceptions is a short-term side effect, with full pigmentation returning within a few months, potentially necessitating a delay of future treatments to allow these re-pigmentation.
Type I: Always burns; never tans
Type II: Burns easily, tans minimally
Type III: Burns moderately; tans gradually to light brown
Type IV: Burns minimally; always tans well to moderately brown
Type V: Rarely burns; tans profusely to dark brown
Typical Side Effects of Laser Tattoo Removal
Redness: the body’s immune response involves blood and its components arriving at the site of a stimulus
Blistering: likely the most significant side effects; blisters can be raised and cover up to the entire area of the tattoo; part of the normal healing process. These blisters are only an expansion of the very outermost layer of skin and will not lead to scarring. They can be filled with fluid that can take the color of the ink being removed. Helpful to the healing and tattoo removal process.
Scabbing: can occur is there is any pinpoint bleeding or blistering encounterd. These scabs should be kept on the skin for as long as possible because they will draw out ink from the tattoo.
Hypopigmentation: loss of color in skin because of destruction of melanin; a temporary condition that resolves itself within weeks or months as melanin is reproduced and skin color returns; somewhat prevalent in Skin Type V and VI (especially those of African descent)
Contra-indications for Tattoo Removal
Patients that should not be treated
Pregnancy, or a patient trying to become pregnant. There is an unknown but possible risk of transfer of ink to fetus. Additional slight risk of miscarriage due to stress of procedure.
Breast feeding, again because of unknown but possible risk of transfer of ink to baby.
Chemotherapy within last 6 months because of sensitivity to light and compromised status of immune system.
Accutane within last 6 months.
Sunburned skin in area of tattoo
Patients to exercise extra precautions or care with
Allergic reaction to ink, primarily red tattoo ink, may lead to increased chance of anaphylaxis. Either should not be treated or patient should take Claritin or Benadryl prior to treatment and for at least 3 days while they are healing.
Skin types IV or above because of increased chance of hypo or hyperpigmentation and scarring.
History of keloid scarring because of increased chance of further keloid scars.
History of hyper or hypopigmentation
Antibiotic use may cause an increase sensitivity to light.
Other Conditions to Consider
Chronic disease (ex. Diabetes> because of delay in healing. These patients may need longer between treatments to heal fully.
Older clients may also take longer to heal.
In general, a patient’s first few treatments will result in more significant side effects that later treatments. Once the amount of ink in the tattoo has decreased, the immune response associated with the treatment will be less obvious. Additionally, the patient will be more conditioned to the treatment.
Cover area with bandage for three days
Apply antibiotic cream (Neosporin or triple antibiotic ointment) every 8 hours for three days
Let area dry out after three days so that it will heal faster
Do not soak in water until all blisters and scabs are completely healed
Okay to shower but patient should keep treated area out of water as much as possible
Patient should return for follow up treatment after 4 to 6 weeks.