Patch test study of 90 patients with tattoo reactions: Negative outcome of allergy patch test to baseline batteries and culprit inks suggests allergen(s) are generated in the skin through haptenization

The allergen or allergens responsible for tattoo reactions are not present directly in tattoo ink stock products. This is despite the fact that clinical histories suggest that the vast majority of clinical reactions, especially reactions to red and red nuances, are likely to be allergic events caused by the injected inks. We suggest that the responsible allergen results from a complicated and slow process of haptenization, which may even include photochemical cleavage of red azo pigment.