Allergic reactions to tattoos: Retrospective analysis of North American Contact Dermatitis Group data, 2001-2016

Hypersensitivity to permanent tattoos: Literature summary and comprehensive review of patch tested tattoo patients 1997-2022

We outline constituents of tattoo and permanent make-up ink with regard to inflammatory tattoo reactions and population-based confounders. The comprehensive review of patch-tested tattoo patients between 1997 and 2022 shows that tattoo allergy cannot be reliably diagnosed via patch testing with today's knowledge. Weak penetration and slow haptenization of pigments, unavailability of pigments as test allergens and a lack of knowledge concerning relevant epitopes hamper the diagnosis of tattoo allergy. Patch testing p-phenylenediamine and disperse (textile) dyes is not able to close this gap. Sensitization to metals was associated with all types of tattoo complications, although often not clinically relevant for the tattoo reaction. Binders and industrial biocides are frequently missing on ink declarations and should be patch tested. The pigment carbon black (C.I. 77266) is no skin sensitizer. Patch tests with culprit inks were usually positive with cheap ink products for non-professional use or with professionally used inks in patients with eczematous reactions characterized by papules and infiltration. Tape stripping before patch testing and patch test readings on Day 8 or 10 may improve the diagnostic quality. The meaningfulness of the categorical EU-wide ban of Pigment Green 7 and Pigment Blue 15:3 is not substantiated by the presented data.

Nickel and tattoos: Where are we?

Tattoos are not mentioned as a source of exposure to nickel. Traces of nickel are, however, almost inevitably found in tattoo inks as impurities and sometimes in tattooed skin. Whether nickel in tattoos has any health consequence is debated. We performed a narrative review of what is currently known about this topic. Today, nickel is frequently detected in inks, but at highly variable levels. It appears to be at higher concentrations in green, blue, and sometimes brown and violet inks. Only nickel allergy in tattooed individuals and nickel-associated tattoo ink allergy are addressed in the literature. Reports of tattoo ink allergy related to nickel are rare and heterogenous. Authors often neglect possible implications of other metals or dyes. A positive patch test is not enough to confirm the role of nickel in a reaction observed after tattooing. We found no report of any systemic complication attributed to nickel from tattoos. The Council of Europe ResAP(2008)1 bans the presence of nickel at high levels in tattoo inks, which is a safety net for individuals with nickel allergy. Large epidemiologic case-control studies with systematic biopsies on normal and inflamed tattoos and patch testing would help to understand the role of nickel in tattoo ink allergies.

Formaldehyde Release From Predispersed Tattoo Inks: Analysis Using the Chromotropic Acid Method

BACKGROUND

Allergic contact dermatitis to tattoo ink may last from weeks to years. Formaldehyde is a strong sensitizer that may be present in predispersed tattoo inks.

OBJECTIVES

The aim of this study was to evaluate the presence of formaldehyde in predispersed tattoo inks using the chromotropic acid method.

METHODS

Tattoo inks from 39 companies were evaluated. Inclusion criteria included availability to purchase inks online through US tattoo product wholesalers or individual Web sites. Brands were grouped based on prevalence of use: common, uncommon, or rare. For common brands, 8 colors (primary colors, secondary colors, black, and white) were purchased. For uncommon and rare brands, 5 colors (primary colors, black, and white) were purchased. Each ink was tested with standard chromotropic acid method procedures; concentration of formaldehyde released was quantified using spectrophotometry.

RESULTS

In total, 127 tattoo inks were purchased and tested. Ninety-three (73%) tested positive for formaldehyde release; 34 (27%) tested negative. Formaldehyde release did not correlate with color or brand. At least 1 ink from all brands (except 1) was positive for formaldehyde release.

CONCLUSION

Approximately three-quarters of selected US tattoo inks tested positive for formaldehyde release. Clinicians should be aware of tattoo ink as a potential source of formaldehyde.