Identification of pigments related to allergic tattoo reactions in 104 human skin biopsies.

BACKGROUND

Red tattoos are prone to allergic reactions. The identity of the allergen(s) is mostly unknown.

OBJECTIVES

Chemical analysis of human skin biopsies from chronic allergic reactions in red tattoos to identify culprit pigment(s) and metals.

MATERIAL AND

METHODS

One hundred four dermatome biopsies were analyzed by matrix-assisted laser desorption/ionization tandem mass spectrometry (MALDI-MS/MS) for identification of commonly used organic pigments. Metal concentrations were assessed by inductively coupled plasma (ICP)-MS and x-ray fluorescence (XRF). Fourteen patients had cross-reactions in other red tattoos.

RESULTS

In total, the identified pigments were mainly azo Pigment Red (P.R.) 22 (35%), P.R. 210 (24%), P.R. 170 (12%), P.R. 5 (0.9%), P.R. 112 (0.9%), and Pigment Orange (P.O.) 13 (11%). P.R. 122 (0.9%) and Pigment Violet (P.V.) 23 (8%) were also common. P.R. 22, P.R. 170, and P.R. 210 also dominated in patients with cross-reactions. In 22% of the biopsies, no red pigment was detected. Element analysis indicated the presence of the sensitizers nickel and chromium.

CONCLUSIONS

P.R. 22, P.R. 170, and P.R. 210 were identified as the prevailing pigments behind chronic allergic reactions in red tattoos. The epitope causing the reaction might be a pigment-degradation product. Metal contamination may derive from different sources, and its role in red tattoo allergy cannot be ascertained.