Contact Dermatitis Update for 2025

Kicking off the first day of lectures in Miami, David Cohen, MD, MPH, provided an insightful overview of contact dermatitis, focusing on allergens dermatologists should monitor in 2025. He highlighted shifting trends, noting that while nickel and methylisothiazolinone (MI) remained the top 2 allergens, fragrance mix components like hydroperoxides of linalool and benzisothiazolinone (BIT) moved up the rankings. Through patient case studies, Dr Cohen explored common offenders such as MI, lanolin, and fragrance, emphasizing the rising prevalence of MI sensitization, which increased from 2.5% in 2010 to 13.8% in 2023. Despite being a common test allergen, MI testing may miss up to 60% of BIT sensitizations, prompting the need for broader testing strategies. Lanolin, designated as the 2023 allergen-of-the-year and commonly manifesting as contact dermatitis on the lips or genitals, was noted to be more likely seen in patients with concurrent atopic dermatitis. Fragrance sensitivity was also prevalent, with nearly 1 in 4 patients with contact dermatitis reacting to allergens like hydroperoxides of linalool and limonene, which require specific inclusion in patch test panels.

Dr Cohen also addressed systemic contact dermatitis, a condition triggered by systemic exposure to allergens and often misdiagnosed due to its varied presentations, such as baboon syndrome or dyshidrotic hand eczema. He concluded with a focus on sulfites, the 2024 allergen-of-the-year, found in cosmetics, food, beverages, and pharmaceuticals, including topical antifungals and local anesthetics. By emphasizing the importance of recognizing new trends, refining diagnostic tools, and expanding patch test panels, Dr Cohen underscored the evolving landscape of allergen detection and management in dermatology.