What did the researchers do?
Ines Schreiver and her colleagues at the German Federal Institute for Risk Assessment already knew that tattoo needles contain chromium and nickel. They investigated whether the two metals enter the skin from the needle during the tattoo process – due either to the abrasion of very small particles or a chemical reaction with the ink. There was no previous research in this area.
How did they proceed?
First they examined skin and lymph node samples taken from five tattooed people using scanning electron microscopy. The donors had no tattoo-related health problems.
The research team then examined skin and lymph node samples from a tattooed patient with a severe allergic skin reaction to the tattoo. The tattooed area (an eagle) was red and swollen.
The team also tested two standard types of ink:
- carbon black ink
- titanium dioxide (TiO2) white ink, which is used to create different colours for the tattoos.
Neither of the inks contained steel particles before the tattooing process.
What was the result?
Scanning electron microscopy revealed that the needles used for tattooing with ink containing titanium dioxide had higher wear than the needles used for tattooing with black ink.
The research team found very small chromium-nickel-iron particles in the skin and lymph nodes. Tattoo needles contain nickel (6-8 %) and chromium (15-20%). Although the needles are made of steel, nickel (6-8%) and chromium (15-20%) are often added in order to protect them against acid and chemical decomposition. Both metals are known allergens.
The research team believes that the metals from the needle were deposited in the body. They were then transported into the lymph nodes with the lymphatic fluid. Another possibility is that the metal particles were transported to the lymph nodes by phagocytes, the body’s immune defence cells. The T lymphocytes in the lymph nodes can then trigger a type IV allergy. This type IV allergy is cited in the scientific literature as the second most common side effect of tattoos.
What is important about the study?
It demonstrates that nickel and chromium can also be deposited in the body through tattoo needles and can therefore be the cause of an allergy.
Original study: Schreiver I et al. Distribution of nickel and chromium containing particles from tattoo needle wear in humans and its possible impact on allergic reactions. Part Fibre Toxicol 2019;16: 33
Tattoos can trigger allergies. ECARF, January 2019.