Most tattoos are placed by professionals, with very fine needles and with devices that place the pigment uniformly within the skin. They may include many different types of pigment to make multi-color tattoos, and they are usually very crisp and very stable over time.
Non-artists may apply home-made inks with non-standard tools to tattoo the skin. This may be done in certain parts of the world for cultural traditions. It is sometimes done in prison or in gangs as ways of marking social relationships. These are usually blue-black and somewhat smudged in appearance over time.
When the skin is wounded, foreign material can enter and may leave a grey pigmentation within the wound. This is usually seen after a cycling accident, injury from a pencil tip, or, in the worst of circumstances, after an explosion.
Landmarks used to align medical treatments, most commonly radiation therapy, need to be exquisitely constant from treatment to treatment. Small dots are often placed in key areas to provide landmarks with which to align the treatment at each appointment.
Permanent and “semi-permanent” make-up is placed in a tattoo-like fashion. Cosmetic tattoos may also be placed to camouflage skin color, for example in nipple reconstruction as part of reconstructive breast surgery after masetectomy.
Even with sterile needles (which must be ensured with the tattoo artist prior to application!), there is a risk of infection with bacteria or virusus. These may be self limited and local, but there is a risk of more severe scarring infection if treatment is not prompt and appropriate.
Allergies and other hypersensitivity reactions
An allergic reaction to a pigment in a tattoo may develop shortly after the procedure or many years after. True allergy manifests with itch and a red inflammation. Another process called a granuloma occurs when the body tries unsuccessful to engulf the pigment, which it recognizes as a foreign body. This appears as a raised lumpy area in th tattoo. It most commonly occurs in red tattoos, but can occur in green and yellow as well, and has been reported in most colors.
Hypersensitivity (allergies) may also develop to tattoo pigments. An allergy to mercury in the red color pigment called cinnabar was very common, but is no longer used. A chemical called para-phenylenediamine, which is applied to the skin in temporary henna tattoos, frequently causes contact dermatitis.
Some pigments, most notable in yellow and red tattoos, can cause sensitivity to the sun. This area in the tattoo will form a sunburn rash with sun exposure.
In people who are prone and in certain body areas, tattooing can cause keloids, large scars which are disproportionate to the level of skin injury at the site.
Interference with medical procedures
Tattoos may interfere with MRI and may complicate epidural placement.
With time, many decide they no longer want to have a tattoo, for a variety of reasons. Laser tattoo removal can be very effective but has some limitations. It is very effective for black pigment, but no lasers currently exist that can reliably remove yellow, green, or red tattoos. White tattoos may contain titanium, which turns black when exposed to laser. Unfortunately, this blackened titanium cannot be removed.
Several lasers are available for laser tattoo removal. Most commonly, ruby, alexandrite, and ND:YAG lasers are used. The treatment is feels like the snapping of a rubber band and can be made more comfortable by the application of a topical anesthetic cream. The treatment carries a risk of lightening or darkening the surrounding skin. This is usually reversible. The procedure carries a risk of scarring in some individuals.
Herzelia Dermatology and Laser Center offers ruby and ND:YAG lasers for tattoo removal.
The information above is a partial and general information and cannot replace the needed specific medical examination and consultation