Prevalence of Contact Allergy to Colophonium in Dermatitis Patients: A Systematic Review and Meta-Analysis

Colophonium is present in many consumer and industrial products, including medical devices and cosmetic products. Due to its extensive use, there is an inherent risk of developing a contact allergy to it. Previous studies have shown that the prevalence rate of contact allergy to colophonium is around 1%-2%. This meta-analysis aimed to estimate the current prevalence of colophonium contact allergy in dermatitis patients. Two authors independently searched PubMed, Embase and Web of Science for studies reporting the prevalence of contact allergy in dermatitis patients with inception through 30 June 2025. A proportion meta-analysis was conducted to estimate the pooled prevalence of colophonium contact allergy. Seventy-three studies involving 459 757 patients with dermatitis were included. The pooled prevalence of colophonium contact allergy was 3.54% (95% CI, 3.01-4.16) with an I ² of 98.6% (95% CI, 98.5-98.7) and a clinical relevance of 39.42% (95% CI, 37.94-40.92). Significant sensitization rates were observed in different geographic regions, with the highest prevalence found in Southeast Asia (6.83%). The prevalence rate was 3.31% among children and 1.31% among adults; however, these differences were not statistically significant. The prevalence rate was 4.74% for patients with AD and 4.87% for patients without AD, with no statistically significant difference. Colophonium sensitization has remained stable in recent decades, highlighting the substance's widespread presence in products. This emphasizes the need for prevention and better registration.