TREE NUT ALLERGY

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。子项目和研究者（PI）可能从另一个NIH来源获得主要资金，因此可以在其他CRISP条目中表示。所列机构为中心，不一定是研究者所在机构。人们曾经认为坚果过敏，包括花生和树坚果（核桃，杏仁，腰果，山核桃，巴西坚果，榛子，开心果，松子和澳洲坚果），是一个终身的问题。最近的研究表明，大约20%的儿童长大后对花生过敏，但没有研究确定有多少树坚果过敏的儿童会长大。我们假设，有相当数量的早发树坚果过敏的儿童会在童年后期对树坚果产生耐受性。我们还假设，RAST（放射性过敏吸附试验），测量食物特异性IgE水平，将是最有用的预测临床反应树坚果，我们将能够预测通过口服挑战在不同的特异性IgE水平的几率。将从约翰霍普金斯的儿科过敏诊所和伍德博士的私人诊所招募200至400名0 - 21岁的被诊断为树坚果过敏的患者，无论是通过摄入后过敏反应的临床病史，还是通过阳性树坚果皮肤试验或特异性IgE水平的病史。将收集人口统计学和临床信息，包括患者的年龄、性别、初始症状、皮肤试验结果、RAST结果、食物激发结果、其他食物过敏和相关特应性疾病（如哮喘、过敏性鼻炎或特应性皮炎）。同意参加研究程序阶段的患者将完成详细的问卷调查，并接受病史、体格检查、皮肤和RAST测试。所有在过去一年中对树坚果没有反应并且所有树坚果IgE水平低于10 kU/L的4岁或4岁以上的患者将接受双盲，安慰剂对照食物挑战（DBPCFC）。DBPCFC将被推迟，如果任何一种树坚果IgE水平大于10 kU/L，患者在过去一年中作为常规护理的一部分进行的树坚果挑战失败，或意外暴露后的近期反应史足以令人信服，挑战将是不必要的和潜在的危险，则患者将被视为树坚果过敏。我们预计10%到20%的儿童长大后会对坚果过敏。我们相信，我们会发现树坚果IgE水平是确定哪些患者值得挑战的最佳指南。完成后，我们将能够为患者和临床医生提供关于坚果过敏的自然史，随着时间的推移重新评估的价值以及适当使用口服食物挑战的明确指南。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. It was once thought that nut allergy, including peanut and tree nuts (walnut, almond, cashew, pecan, Brazil nut, hazelnut, pistachio, pine nut, and macadamia nut), was a lifelong problem. Recent studies have shown that about 20% of children outgrow their peanut allergy, but there have been no studies performed to determine how many children with tree nut allergy will outgrow it. We hypothesize that a significant number of children with early onset tree nut allergy will become tolerant of tree nuts later in childhood. We also hypothesize that the RAST (radioallergosorbent test), which measures food-specific IgE levels, will be the most useful predictor of clinical reactivity to tree nuts, and that we will be able to predict the odds of passing an oral challenge at different specific IgE levels. Two to four hundred patients aged 0 - 21 years who have been diagnosed with tree nut allergy, either by clinical history of an allergic reaction after ingestion, or by history of a positive tree nut skin test or specific IgE level without prior ingestion, will be recruited from the Pediatric Allergy Clinic at Johns Hopkins and Dr. Wood's private practice. Demographic and clinical information, including the patient's age, sex, initial symptoms, skin test results, RAST results, food challenge results, other food allergies, and associated atopic diseases such as asthma, allergic rhinitis, or atopic dermatitis, will be collected. Patients who consent for the procedural phase of the study will complete a detailed questionnaire and undergo a history, physical exam, and skin and RAST testing to tree nuts. All patients aged 4 years or older who have not had a reaction to a tree nut in the past year and who have all tree nut-IgE levels less than 10 kU/L will be offerred double-blind, placebo-controlled food challenges (DBPCFC). The DBPCFCs will be deferred and the patient will be deemed tree nut-allergic if any one of the tree nut-IgE levels are greater than 10 kU/L, the patient has failed a previous tree nut challenge in the past year as part of their routine care, or the history of a recent reaction after accidental exposure is convincing enough that a challenge would be unnecessary and potentially dangerous. We expect that between 10 and 20% of children outgrow their tree nut allergy. We believe that we will find that tree nut-IgE levels are the best guide to determine which patients merit challenge. Upon completion, we will be able to provide clear guidelines for both patients and clinicians on the natural history of tree nut allergy, the value of re-evaluation over time, and the appropriate use of oral food challenges.