Analysis of Patch Testing for Allergic Contact Dermatitis in Adults Versus Geriatrics: A 7-Year Retrospective Analysis of 342 Positive Patch Test Cases

This review discusses the need for an updated 'European hair cosmetic series' to include common contact allergens and remove outdated substances based on current evidence and regulations, but it reports no new results.

In this study, researchers observed that atopic dermatitis may alter the appearance of allergic patch test reactions, demonstrating specific patterns like perifollicular erythema and yellowish areas that could aid in interpreting patch tests using dermoscopy, particularly in ambiguous cases.

This study found that 9% of tested patients had positive patch test reactions linked to hair care products, with most reactions clinically relevant and commonly involving allergens like p-phenylenediamine.

This study reported that para-phenylenediamine and toluene-2,5-diamine are the main sensitizers in hair dye-related allergic contact dermatitis, with significant cross-reactivity to several other compounds.

This study analyzed patch test results to identify allergens causing scalp contact dermatitis, finding nickel, cobalt, and balsam of Peru among the most common in the patient population.