What Is the Main Idea?
Delayed allergic reactions, also known as delayed hypersensitive reactions, occur days, weeks or even months after exposure. This post deals with delayed reactions to tattoo ink, based on the case report “Delayed-Type Hypersensitivity Reaction to Red Tattoo Ink Triggered by Ledipasvir/Sofosbuvir for Hepatitis C” and published in the journal Case Reports in Dermatology. Discover why these reactions occur, why they’re difficult to predict and why it’s important to know about them.
What Else Can You Learn?
Learn the difference between an allergy to tattoo ink, keloids and short-term changes in your tattoo. You can also find out what components of different tattoo inks are responsible for allergies.
Tattoos and Allergic Reactions
Did you know that it’s possible to have an allergic reaction to tattoo ink? An allergic reaction is defined as your immune system overreacting to something harmless or relatively harmless. Skin-related allergic reactions can include rashes, itching, flaky or scaly skin, small blisters, and swelling. A common allergic reaction to a tattoo is a red, bumpy, persistent rash that can be very itchy. Interestingly, it can occur in the first days after you get the tattoo or months or years later. To the best of my knowledge, there are no reports of anaphylaxis (the most serious and life-threatening allergic reaction) in response to a permanent tattoo.
There are also times that parts of your tattoo may feel raised for a short time. This can be due to internal and external factors, such as dehydration, tension, or even extreme heat or cold. Remember that a tattoo becomes part of the structure of your skin, which reacts dynamically to your physical state and environment. That means the tattoo will also react.
Are Keloids an Allergic Response?
Note that allergic rashes or slightly raised tattoos are not the same as the formation of keloids. These are enlarged, raised scars that can form anywhere that you have trauma to your skin. They can take months to form and will look like thickened skin. Anyone can get keloids, but not everyone does. If you know that you’re prone to them and you’re getting a tattoo, consider talking to a dermatologist about how you might prevent them occurring.
What Triggers the Allergic Response?
Getting back to allergic reactions: Red tattoo pigments are the most common triggers of this response. This used to be due to the presence of the mercury-derived pigment cinnabar in red inks. Even though this component has been replaced by cadmium red, sienna, sandalwood and other substances, reactions to red ink persist. Because there are multiple ingredients, it is difficult to isolate the component that’s causing the problem.
Other tattoo pigments can also trigger allergic reactions due to metallic components such as nickel, chrome and cobalt, and preservatives like formaldehyde. The carbon-based pigments in black tattoos can cause issues on their own or break down over time to cause issues. Yellow tattoos have particular sensitivity to sunlight, with photoreactive decay potentially leading to allergens being created. The mineral components of blue ink can also be an issue.
What Is a Delayed Hypersensitive Reaction?
The phenomenon of an allergic reaction occurring days, weeks or months after exposure is known as a delayed hypersensitive reaction. Normally, delayed hypersensitive reactions are expected two to three days after exposure, but as mentioned, the time limit is different with tattoos.
This post was inspired by the case of a 51-year old cisgender man, described in the case report “Delayed-Type Hypersensitivity Reaction to Red Tattoo Ink Triggered by Ledipasvir/Sofosbuvir for Hepatitis C”. For four months, the man had had itchy lesions on the red areas of a multi-colored tattoo on his back. They had appeared one week after he started taking ledipasvir/sofosbuvir for a hepatitis C infection. The examination of the lesions showed that he had a delayed hypersensitive reaction to red tattoo ink. Treatment produced a mild improvement.
Can You Test for the Risk of Delayed Hypersensitive Reactions?
Interestingly, when researchers used patch tests on patients with red tattoo reactions, the results were inconsistent, suggesting that this technique is not useful for diagnosing a risk of delayed hypersensitive reactions.
The reason for the reaction — and the reason for the difficulty in diagnosing it — may be a phenomenon related to the metabolism of the tattoo pigments over time. The impact of exposure to the sun, which may cause photochemical breakdown of tattoo pigments, has also been suggested as a cause. The idea is that the pigment might not be an allergen at the time that the tattoo is created, but its breakdown products might cause the reaction.
Immune reconstitution and its related inflammatory syndrome are also mentioned in the paper as reasons for the delayed response. Immune reconstitution is the process of the immune system rebuilding itself after a period of suppression due to disease or medical treatment. Immune reconstitution inflammatory syndrome occurs when the rebuilding immune system overreacts to previously acquired infections or to allergens in the body.
How Common Are Allergic Reactions to Tattoos?
Reports of immune or allergic reactions to tattoos are quite rare. In quite a few cases, the reports of delayed hypersensitive responses involve patients receiving treatments for hepatitis C or HIV and then developing the allergy. These therapies include ledipasvir/sofosbuvir and antiretrovirals, which can lead to immune reconstitution.
Reports of this type will hopefully lead to research into how this occurs as well as increasing the awareness of such phenomena among healthcare workers. It is also worth knowing that drugs and other changes can lead to an immune reaction or tattoo allergy. If it happens, you will know to talk to a specialist right away, rather than waiting to see if it disappears.
Note: Two of the authors of the paper declared that they receive personal fees and/or nonfinancial support from pharmaceutical companies. It is normal for authors to declare this in case it might be perceived as a conflict of interest. For more detail, see the Conflict of Interest Statement at the end of the paper.