Gray C L, Levin M E, Du Toit G
Division of Allergology, Department of Paediatrics and Child Health, Red Cross War Memorial Children's Hospital, Cape Town, and Faculty of Health Sciences, University of Cape Town, South Africa.
S Afr Med J. 2017 Sep 22;107(10):904-909. doi: 10.7196/SAMJ.2017.v107i10.12418.
Atopic dermatitis (AD) is an early and important step in the propagation of the allergic march, enhancing food and respiratory allergies via epicutaneous sensitisation to allergens.
To determine the prevalence and patterns of aeroallergen sensitisation, asthma and allergic rhinitis in South African (SA) children with AD.
This was a prospective, observational study in a paediatric university hospital in Cape Town, SA. Children with moderate to severe AD, aged 6 months - 10 years, were recruited randomly and investigated for food sensitisation and allergy. They were assessed for sensitisation to aeroallergens by the immuno solid-phase allergen chip test. House-dust mite DerP and DerF, dust mite Eur m, Timothy grass, Bermuda grass, tree pollen, mould (Alternaria), cat and dog sensitisation patterns were analysed. Symptoms of asthma and allergic rhinitis were elicited using a questionnaire modified from the International Study of Asthma and Allergies in Childhood study questions.
One hundred participants (59 black Africans and 41 of mixed ethnicity) were enrolled (median age 42 months). Of the participants, 39% had symptoms of asthma and 53% symptoms of allergic rhinitis; 89% tested positive to at least one aeroallergen, most commonly house-dust mite DerP or DerF (81%), dust mite Eur m (51%), Timothy grass (36%) and cat (35%). Asthma, allergic rhinitis and aeroallergen sensitisation all increased with increasing age, while food allergy decreased with age. Food allergy was not an independent risk factor for respiratory allergies. Children were sensitised to indoor allergens (house-dust mite, pets) from an early age, while pollen allergies increased with age.
In this cohort of SA children with moderate to severe AD, comorbidity with respiratory allergies was high. The prevalence of respiratory allergies increased with age while food allergy decreased with age, in keeping with the pattern of the allergic march. Seasonal allergies increased with age, while house-dust mite and pet allergy peaked in younger children, in keeping with early exposure via a defective skin barrier. Early and effective restoration of the skin barrier in AD may be a target for reducing aeroallergen-related diseases.
特应性皮炎（AD）是过敏进程发展早期的一个重要阶段，通过经皮致敏原致敏增强食物和呼吸道过敏。
确定南非（SA）患AD儿童的气传变应原致敏、哮喘及变应性鼻炎的患病率和模式。
这是一项在南非开普敦一家儿科大学医院进行的前瞻性观察性研究。随机招募6个月至10岁的中重度AD患儿，并对其进行食物致敏和过敏调查。通过免疫固相变应原芯片试验评估他们对气传变应原的致敏情况。分析屋尘螨DerP和DerF、粉尘螨Eur m、梯牧草、百慕大草、树花粉、霉菌（链格孢属）、猫和狗的致敏模式。使用根据儿童哮喘和变应性鼻炎国际研究问题修改的问卷来引出哮喘和变应性鼻炎的症状。
共纳入100名参与者（59名非洲黑人及41名混血儿）（中位年龄42个月）。参与者中，39%有哮喘症状，53%有变应性鼻炎症状；89%对至少一种气传变应原检测呈阳性，最常见的是屋尘螨DerP或DerF（81%）、粉尘螨Eur m（51%）、梯牧草（36%）和猫（35%）。哮喘、变应性鼻炎和气传变应原致敏均随年龄增长而增加，而食物过敏随年龄增长而减少。食物过敏不是呼吸道过敏的独立危险因素。儿童从小就对室内变应原（屋尘螨、宠物）致敏，而花粉过敏随年龄增长而增加。
在这一队列中重度AD的南非儿童中，呼吸道过敏合并症的发生率很高。呼吸道过敏的患病率随年龄增长而增加，而食物过敏随年龄增长而减少，这与过敏进程的模式一致。季节性过敏随年龄增长而增加，而屋尘螨和宠物过敏在幼儿中达到峰值，这与通过有缺陷的皮肤屏障早期接触有关。AD中早期有效地恢复皮肤屏障可能是减少气传变应原相关疾病的一个目标。
