避免接触食物过敏原是极其重要的。应该教育患者(和家长/看护者,如果患者为儿童)严格避开食物过敏原。营养师的参与可能会有帮助,因为配比不当的排除性饮食可能会导致营养不良。
在预防过敏发生方面,目前的证据并不支持高风险女性在妊娠期间采用脱离抗原的饮食方案。[22]Greer FR, Sicherer SH, Burks AW, et al. Effects of early nutritional interventions on the development of atopic disease in infants and children: the role of maternal dietary restriction, breastfeeding, timing of introduction of complementary foods, and hydrolyzed formulas. Pediatrics. 2008;121:183-191.http://pediatrics.aappublications.org/content/121/1/183.fullhttp://www.ncbi.nlm.nih.gov/pubmed/18166574?tool=bestpractice.com[23]Kramer MS, Kakuma R. Maternal dietary antigen avoidance during pregnancy or lactation, or both, for preventing or treating atopic disease in the child. Cochrane Database Syst Rev. 2012;(9):CD000133.http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD000133.pub3/fullhttp://www.ncbi.nlm.nih.gov/pubmed/22972039?tool=bestpractice.com食物过敏的预防:高质量的系统综述表明:缺乏母亲孕期饮食限制在预防婴儿特应性疾病中发挥显著作用的证据。[22]Greer FR, Sicherer SH, Burks AW, et al. Effects of early nutritional interventions on the development of atopic disease in infants and children: the role of maternal dietary restriction, breastfeeding, timing of introduction of complementary foods, and hydrolyzed formulas. Pediatrics. 2008;121:183-191.http://pediatrics.aappublications.org/content/121/1/183.fullhttp://www.ncbi.nlm.nih.gov/pubmed/18166574?tool=bestpractice.com同样,哺乳期避开过敏原不能预防特应性疾病,但特应性湿疹可能是个例外,尽管需要更多的数据来证实这个结论。系统评价或者受试者>200名的随机对照临床试验(RCT)。一些研究表明,哺乳期母亲避免接触抗原或可降低婴儿湿疹的几率或严重程度;然而,在做出严格结论之前还需进一步的试验。已有数据证明母亲补充 ω-3 多不饱和脂肪酸 (n-3PUFA) 可能降低最大 12 个月龄婴儿鸡蛋过敏的患病率。[24]Klemens CM, Berman DR, Mozurkewich EL. The effect of perinatal omega-3 fatty acid supplementation on inflammatory markers and allergic diseases: a systematic review. BJOG. 2011;118:916-925.http://onlinelibrary.wiley.com/doi/10.1111/j.1471-0528.2010.02846.x/fullhttp://www.ncbi.nlm.nih.gov/pubmed/21658192?tool=bestpractice.com[25]Palmer DJ, Sullivan T, Gold MS, et al. Effect of n-3 long chain polyunsaturated fatty acid supplementation in pregnancy on infants' allergies in first year of life: randomised controlled trial. BMJ. 2012;344:e184.http://www.bmj.com/content/344/bmj.e184.longhttp://www.ncbi.nlm.nih.gov/pubmed/22294737?tool=bestpractice.com需要更进一步的研究确定产前n-3 PUFA对婴儿食物过敏的预防效果。再者,出生后补充n-3 PUFA并未被证实能预防过敏性疾病。[26]D'Vaz N, Meldrum SJ, Dunstan JA, et al. Postnatal fish oil supplementation in high-risk infants to prevent allergy: randomized controlled trial. Pediatrics. 2012;130:674-682.http://www.ncbi.nlm.nih.gov/pubmed/22945403?tool=bestpractice.com
对于有过敏高风险的婴儿,在 4 月龄以上时无需避免辅食添加。[27]Muraro A, Halken S, Arshad SH, et al. EAACI food allergy and anaphylaxis guidelines: primary prevention of food allergy. Allergy. 2014;69:590-601.http://onlinelibrary.wiley.com/doi/10.1111/all.12398/fullhttp://www.ncbi.nlm.nih.gov/pubmed/24697491?tool=bestpractice.com2017 年,美国国立卫生研究院过敏及感染性疾病研究所 (National Institute of Allergy and Infectious Diseases, NIAID) 专家组发布了关于预防高风险婴儿(即,存在重度湿疹鸡蛋过敏或两者皆有的婴儿)花生过敏的修订版指南。[28]Togias A, Cooper SF, Acebal ML, et al. Addendum guidelines for the prevention of peanut allergy in the United States: Report of the National Institute of Allergy and Infectious Diseases-sponsored expert panel. Ann Allergy Asthma Immunol. 2017;118:166-173.https://www.niaid.nih.gov/sites/default/files/addendum-peanut-allergy-prevention-guidelines.pdfhttp://www.ncbi.nlm.nih.gov/pubmed/28065802?tool=bestpractice.com在 LEAP(及早了解花生过敏)研究得出结果之后,专家组得出的结论认为,最早在 4 至 6 个月龄时,便可以将符合年龄的含花生食物引入这些婴幼儿的饮食中(需要注意的是,在引入花生之前,强烈建议考虑进行花生特异性 IgE 测定、皮肤点刺试验或者两者皆进行,以确定是否应该添加,如果应该,再确定首选的添加方法)。LEAP 是一项随机临床试验,旨在研究在严重特应性皮炎或鸡蛋过敏婴幼儿(即存在花生过敏高风险的婴幼儿)中预防花生过敏的策略,该试验发现,在第 4-11 月龄引入花生的婴儿中,有 1.9% 发生花生过敏,而在 60 月龄之前避免摄入花生的婴幼儿中,有 13.7% 发生花生过敏。[29]Du Toit G, Roberts G, Sayre PH, et al. Randomized trial of peanut consumption in infants at risk for peanut allergy. N Engl J Med. 2015;372:803-813.http://www.nejm.org/doi/full/10.1056/NEJMoa1414850#t=articlehttp://www.ncbi.nlm.nih.gov/pubmed/25705822?tool=bestpractice.com一项为期 12 个月的随访研究 (LEAP-ON) 发现,早期食用花生的益处是持久性的。[30]Du Toit G, Sayre PH, Roberts G, et al. Effect of avoidance on peanut allergy after early peanut consumption. N Engl J Med. 2016;374:1435-1443.http://www.nejm.org/doi/full/10.1056/NEJMoa1514209#t=articlehttp://www.ncbi.nlm.nih.gov/pubmed/26942922?tool=bestpractice.com在 EAT(询问耐受度)研究中,对于普通人群中完全接受母乳喂养的婴幼儿(即并非根据发生食物过敏的风险进行选择),在 3 至 6 个月龄之间于饮食中引入花生和鸡蛋,结果显示,对于坚持摄入这一饮食的婴幼儿,此举对花生和鸡蛋过敏的发生具有防护作用。[31]Perkin MR, Logan K, Tseng A, et al. Randomized trial of introduction of allergenic foods in breast-fed infants. N Engl J Med. 2016;374:1733-1743.http://www.nejm.org/doi/full/10.1056/NEJMoa1514210#t=articlehttp://www.ncbi.nlm.nih.gov/pubmed/26943128?tool=bestpractice.com然而,坚持摄入含过敏原食物(在 3-6 个月龄期间引入)的饮食是很困难的。[31]Perkin MR, Logan K, Tseng A, et al. Randomized trial of introduction of allergenic foods in breast-fed infants. N Engl J Med. 2016;374:1733-1743.http://www.nejm.org/doi/full/10.1056/NEJMoa1514210#t=articlehttp://www.ncbi.nlm.nih.gov/pubmed/26943128?tool=bestpractice.com在该研究中,其他食物过敏原(如牛奶、芝麻、白鲑或小麦)的早期引入未显示出保护作用。