White Jonathan M L, Goon Anthony T J, Jowsey Ian R, Basketter David A, Mak Rose K H, Kimber Ian, McFadden John P
Department of Cutaneous Allergy, St. John's Institute of Dermatology, St. Thomas' Hospital, London SE1 7EH, UK.
Contact Dermatitis. 2007 May;56(5):247-54. doi: 10.1111/j.1600-0536.2006.01066.x.
Experimental and clinical oral tolerance to contact allergens has been reported sporadically, most notably in respect of nickel, and is generally assumed to be an uncommon phenomenon. There has recently been increased understanding of the immunological mechanisms inducing and maintaining oral tolerance. There are several contact allergens, including fragrance, antioxidant, and preservative chemicals, to which subjects are exposed through both cutaneous and oral routes. We examine the possibility that oral tolerance to contact allergens may be more common than previously thought. Animal models of oral tolerance to contact allergens indicate that cutaneous exposure to small, subsensitizing doses of contact allergens might negate any subsequent attempts to induce tolerance by oral administration. Extrapolating these observations to common human practises raises the possibility that application of contact allergens (fragrances, preservatives and antioxidants) in consumer products used by children could prevent or inhibit the later acquisition of specific tolerance resulting from 'natural' dietary exposure after weaning. Existing data on formaldehyde may conflict with this theory, though this could be explained by allergen specificity. We propose that further work in this area is needed.
实验性和临床性的对接触性过敏原的口服耐受已偶有报道，最显著的是针对镍，并且通常被认为是一种不常见的现象。最近，人们对诱导和维持口服耐受的免疫机制有了更多的了解。有几种接触性过敏原，包括香料、抗氧化剂和防腐剂化学品，受试者可通过皮肤和口服途径接触到这些过敏原。我们研究了对接触性过敏原的口服耐受可能比以前认为的更为常见的可能性。对接触性过敏原的口服耐受的动物模型表明，皮肤接触小剂量、亚致敏剂量的接触性过敏原可能会使随后通过口服给药诱导耐受的任何尝试无效。将这些观察结果外推到常见的人类行为中，就产生了一种可能性，即儿童使用的消费品中接触性过敏原（香料、防腐剂和抗氧化剂）的应用可能会预防或抑制断奶后“自然”饮食接触导致的特定耐受的后期获得。关于甲醛的现有数据可能与这一理论相矛盾，不过这可以用过敏原特异性来解释。我们建议在这一领域需要进一步开展工作。
