Nowadays, more and more people are choosing to get tattoos. If you have ever wondered how tattoos work, including the layer of skin they are deposited in and why they are permanent, this article is for you.

We will also discuss how tattoo ink, being a foreign substance, interacts with the immune system and explore the potential risks of getting a tattoo.

Additionally, we will cover how tattoo laser removal works. Let’s dive in and explore the fascinating world of tattoos!

The Epidermis: The Top Layer

In order to understand how tattoos work, we first need to cover a few key features of the skin. Here, we have a skin dissection from the mid-back of a cadaver.

The first layer we will discuss is the top layer, referred to as the epidermis. If I show you the cut edge, you can see two layers that make up the entirety of the skin. The darker, thinner layer, which appears almost paper-thin to the naked eye, is the epidermis. Despite its thin appearance, the epidermis can be over 50 cell layers thick in certain areas of the body.

Composition of the Epidermis

Zooming into the epidermis, we see that it is composed of epithelial tissue, specifically stratified squamous epithelium.

Don’t let the name “stratified squamous epithelium” throw you off; “stratified” means multiple cell layers thick, and “squamous” refers to flat cells because the cells on the very top of the epidermis have a flat shape.

The deeper, thicker, and lighter-colored layer is the dermis, which we will discuss shortly.

How The Tattoos Become Permanent

Depositing tattoo ink into the epidermis wouldn’t be a great strategy if you wanted the tattoo to be permanent. This is because the nature of the tissue that makes up the epidermis involves cells constantly dividing, turning over, and eventually flaking off.

Therefore, if you want a tattoo to be permanent, the ink needs to be deposited into the next layer, the dermis.

The Dermis: The Permanent Layer

The dermis is composed of a completely different type of tissue than the epidermis. It is made of dense irregular connective tissue. If we were to zoom in on this dense irregular connective tissue, we would see far fewer cells.

The scattered cells present are called fibroblasts or fibrocytes, which produce collagen fibers. These fibroblasts deposit collagen fibers into the spaces or matrix between the cells. The tissue is called “dense” because it contains a large amount of collagen fibers, and “irregular” because these fibers are scattered in all directions.

These collagen fibers and fibrocytes are crucial to our tattoo story. As the tattoo needle deposits the ink, some of that ink becomes suspended within the collagen fibers, and some is deposited within the fibrocytes. What happens next is also very important for the tattoo’s permanence.

Tattoo Ink and Inflammatory Response

When you get a tattoo, ink is deposited into the dermis, the deeper layer of your skin. There are two key factors to consider:

1. Foreign Substance: Tattoo ink is a foreign material that your body recognizes as something that doesn’t belong.
   
2. Microtrauma: The tattooing process involves needle penetration, typically between 50 to 3,000 times per minute, creating microtrauma to the skin.

These two factors trigger the body’s inflammatory response. A critical part of inflammation is vasodilation, where blood vessels in the affected area widen, allowing white blood cells to move into the tissue. These cells work to address the injury and protect the body.

The Role of Macrophages

Among the white blood cells, macrophages play a significant role. Their primary job is phagocytosis, where they engulf foreign substances and dead cellular debris. For example, when you have a cut, macrophages engulf dead cells, bacteria, and even viruses, breaking them down to protect the body.

However, when it comes to larger particles like tattoo ink, macrophages encounter a challenge. While they can engulf the ink, they cannot break it down effectively.

Tattoo Ink Containment: A Body’s Strategy

Since macrophages can’t break down the tattoo ink, the body adopts a containment strategy. The ink is essentially trapped in the area, which helps contribute to the permanence of tattoos.

This containment prevents the ink from spreading to other parts of the body, resulting in the lasting appearance of the tattoo.

However, as many people know, while tattoos are considered permanent, they can fade over time.

Why Do Tattoos Fade Over Time?

When you first get a tattoo, initial fading is common during the healing process. This occurs as the ink becomes more solidified and contained within the skin.

It’s why aftercare is crucial during this period. Infection, sun exposure, or UV light can negatively affect the tattoo’s appearance, dulling its vibrancy.

How Aftercare Impacts Tattoo Longevity

Proper aftercare is essential to preserving your tattoo’s vibrancy. If the area becomes infected, or if the tattoo is exposed to UV light or sunburn, the healing process can be compromised, leading to premature fading.

Even without any infections and diligent aftercare, UV light can still break down ink particles over time, speeding up fading.

The Inevitable Tattoo Fading: What’s Happening?

Even with excellent aftercare, some natural fading will still occur over time. This is due to the ongoing interaction between your body and the tattoo ink.

Macrophages, the white blood cells that engulf tattoo ink, are not permanent. They undergo a process called apoptosis, or programmed cell death.

As these macrophages die, they release the ink they were containing. New macrophages then engulf the released ink, beginning a continuous release-engulf-release cycle throughout the tattoo’s lifetime.

The Breakdown of Tattoo Ink Over Time

Over time, not all released ink particles are engulfed by new macrophages. Some of these ink particles break down into smaller fragments.

These smaller fragments can be transported away from the tattooed area via the lymphatic system. This phenomenon has been confirmed by the discovery of tattoo ink in lymph nodes.

The removal of these small ink particles from the skin, combined with the gradual breakdown of ink, contributes to the natural fading of tattoos over time..

Potential Risks of Tattoos

Getting a tattoo is generally safe, especially when done by a professional. However, there are potential risks involved. We’ll break these down into three categories: Infections, Reactions, and Random Risks. You might be surprised by some of the random ones!

Infections

One of the main risks associated with tattoos is infections. The most common type is a localized infection, which affects the area where the tattoo was applied. Two bacteria commonly responsible for these infections are:

• Staphylococcus aureus (causes staph infections)
  
• Streptococcus pyogenes (causes strep infections)

In addition to localized infections, there’s a potential risk for systemic infections. These include Hepatitis B, Hepatitis C, and HIV, though no documented cases of HIV from tattoos have been reported.

Additionally, a condition called infective endocarditis could develop if bacteria enter the bloodstream and infect the heart’s inner lining.

Most severe infections are rare, especially when you visit reputable tattoo artists who practice proper sterilization. To minimize infection risk, choose professional artists who use sterile equipment and follow proper aftercare routines, especially during the first three weeks after getting a tattoo when the risk of localized infections is highest.

Reactions

Hypersensitivity reactions, or allergic reactions, can occur with tattoos. These are often triggered by the metallic salts in tattoo pigments, such as mercury, chromium, cadmium, cobalt, and nickel. For instance, red ink is more likely to cause an allergic reaction due to its mercury content.

One of the challenges with allergic reactions is that people may not know they are allergic to specific ink ingredients until after getting tattooed.

Unfortunately, some tattoo inks in the U.S. may not list all their ingredients on the label, further complicating the issue. This is why choosing a tattoo artist who uses high-quality, reputable products is essential.

Random Risks

Now, let’s discuss some random risks. One rare risk involves MRI (Magnetic Resonance Imaging). Some individuals with tattoos containing metallic oxides, iron, or titanium report burning sensations or intense pain over their tattoos during an MRI.

This is due to the strong magnetic fields used in MRIs interacting with the metallic ingredients in the ink. While this risk is low—less than 0.3%—it’s something to be aware of.

Another consideration is the potential for tattoos to obscure the detection of skin conditions, such as melanoma (skin cancer). Large or dark tattoos can make it harder to spot changes in the skin.

To mitigate this risk, it’s essential to monitor your tattooed areas closely and discuss any concerns with your dermatologist during regular check-ups.

Tattoo Removal: Methods, Pros and Cons

As time goes on, it’s not uncommon for people to feel differently about their tattoos. Maybe you got the name of a special someone tattooed, but now that person is no longer part of your life, and you want the tattoo removed. Fortunately, laser treatments offer a way to remove unwanted tattoos.

How Laser Tattoo Removal Works

Laser tattoo removal works by using high-intensity laser light to target the tattoo inks and pigments without damaging the surrounding skin.

The laser breaks down the tattoo into smaller ink particles, which can then be naturally removed by the immune system.

The Downsides of Laser Tattoo Removal

While laser tattoo removal can be effective, it has some drawbacks. The procedure typically requires multiple sessions, can be painful, and is often costly.

Additionally, there is a potential risk of scarring or skin discoloration, which should be discussed with your laser technician before starting the treatment.