Objective: To investigate the sensitization to the dispersal of blue 124, a synthetic dye used in textile applications. The chemical properties of this dye allow it to migrate from fabrics to the skin, posing a risk for sensitization and allergic reactions. Materials and Methods: A retrospective analysis of 30,629 consecutive patch test data from 1997 to 2021 in the Triveneto region (Italy) was performed using disperse blue 124 1% in petrolatum. Data were analyzed to assess trends in sensitization rates across different demographics and occupational groups. Results: The prevalence of sensitization to disperse blue 124 was 2.5% (n. 780 patients) and declined over the considered period, reaching a prevalence of approximately 1.5–1.9% in recent years. Sensitization was slightly higher in women (2.7%) compared to men (2.3%, p = 0.053), and in 36–65-year-old individuals (p < 0.05). Painters and textile workers presented a mild increase in sensitization, without reaching the statistical significance. Discussion: Disperse blue 124 sensitization declined significantly over the considered period, probably as result of the reduced use of this dye in textiles available on the Italian market. Its occupational role is limited. Conclusions: Contact dermatitis associated with disperse blue 124 declined over the considered period, but it is still above 1%, indicating the need for monitoring.
