Tattoo allergy—diagnosis on a circuitous route?

Background Decorative tattoos and permanent make-up have been gaining popularity for years. Increasingly, intolerance reactions occur. Methods Literature search of PubMed and reference books on diagnostic and treatment options for tattoo complications. Results At least one third of persistent intolerance reactions to tattoos are allergic reactions. The diagnostic work-up should include the tattoo ink used and, particularly in cases of scattered eczema, other products applied. Pigments penetrate very poorly into the epidermis and are not available as commercial test preparations. Consequently, patch tests very often show (false) negative results in affected individuals. Allergological individual diagnosis and assessment of clinical relevance are rarely possible as the chemical composition of the culprit tattoo ink is usually unknown. Discussion Diagnosis of tattoo allergy is challenging. The IVDK Tattoo Study 2.0 enables the identification of metals and pigments in skin samples, the preparation of individual patch test preparations with pigments, and the investigation of specific T lymphocytes in blood samples. In addition, assessment of the clinical relevance can be improved by exposure data and results of laboratory diagnostics.