- [In German only] Kühn LM et al. Nützliches Wissen zu Tätowierungen. Dermatologie 2023; 74: 543-553.
Besides the colour pigments, tattoo inks contain all kinds of additives. These include solvents, binders, preservatives and surfactants. In 2022, REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals), an EU regulation, came into force that requests mandatory labelling and information for tattooing products as well as a restriction of hazardous ingredients. However, investigations have shown that about 40 per cent of these products do not comply with the REACH requirements.
Tattoos can have dramatic consequences for the skin. In one study, nearly 70 per cent of tattooed people experienced complications. They range from allergies and infections to granulomatous reactions, ulcerations and neoplasia.
Infections are among the most common reactions. They are often caused by poor hygiene. Even the colours themselves can be contaminated. In studies, infectious pathogens were found in 10 to 50 per cent of all samples.
Contact allergies are also common. Depending on previous sensitisation, they can occur within a few days or only after several weeks or months. Red paint is the most sensitive substance. It contains, among other things, synthetic azo dyes, which, together with binders and preservatives, are the main triggers for contact allergic reactions. However, henna colour that is only applied superficially to the skin can also cause allergies. Some products contain p-phenylenediamine (PPD), a strong contact allergen that can cause extensive eczema.
Less common are lichenoid or granulomatous reactions. The formation of pseudolymphomas has also been observed after tattoos. Tattoos can also aggravate existing skin diseases in the sense of the Köbner phenomenon. It has not been proven whether tattoos can also promote tumourigenesis. However, polycyclic aromatic hydrocarbons (PAHs), which are contained in black tattoo ink, for example, and are partly carcinogenic, could contribute to this. They remain in the skin for life and can disturb it sensitively.
Tattoos are an intrusion into the integrity of the skin that, without informed consent, constitutes intentional bodily harm. This makes it all the more important to provide information about cutaneous side effects and possible long-term consequences. This is where dermatologists are most needed. They should be familiar with the ingredients of tattoo inks and their legal standards, and warn people who want to get tattooed of the potential risks.