Various materials in headphones have been reported to cause allergic contact dermatitis (ACD), including acrylates and rubber accelerators.¹ 4,4′-diaminodiphenylmethane (MDA; CAS No. 101-77-9) is a precursor to 4,4′-diphenylmethane diisocyanate (MDI; CAS No. 101-68-8), a rubber additive used to manufacture polyurethane foams. While allergy to MDA is considered a marker for MDI sensitivity, it has also been shown to possess allergenic potential individually.^{2, 3} Although isocyanates are well-known occupational allergens and have recently been shown to contribute to ACD in medical devices and dressings, their role in ACD from consumer products is less understood.^{4, 5} Here, we present a case of MDA as the likely sensitizing allergen from consumer headphones.

据报道，耳机中的多种材料会引起过敏性接触性皮炎 (ACD)，包括丙烯酸酯和橡胶促进剂。¹ 4,4'-二氨基二苯甲烷（MDA；CAS 号 101-77-9）是 4,4'-二苯甲烷二异氰酸酯（MDI；CAS 号 101-68-8）的前体，4,4'-二苯甲烷二异氰酸酯是一种用于制造聚氨酯的橡胶添加剂泡沫。虽然对 MDA 过敏被认为是 MDI 敏感性的标志，但它也被证明具有单独的过敏潜力。^{2, 3}尽管异氰酸酯是众所周知的职业过敏原，并且最近已被证明会导致医疗器械和敷料中的 ACD，但人们对其在消费品中 ACD 中的作用知之甚少。^{4, 5}在此，我们介绍 MDA 可能是消费类耳机中的致敏过敏原的案例。