Tupker R A, De Monchy J G, Coenraads P J, Homan A, van der Meer J B
Department of Dermatology, University Hospital, Groningen, The Netherlands.
J Allergy Clin Immunol. 1996 May;97(5):1064-70. doi: 10.1016/s0091-6749(96)70259-2.
The pathogenetic role of house dust mite in atopic dermatitis remains controversial. Recent studies have shown that intensive epicutaneous contact of house dust mite allergen with premanipulated skin may induce dermatitis. It is, however, uncertain whether such conditions are met during natural contact with house dust mite. In the past, allergen inhalation has been suggested to induce exacerbation of atopic dermatitis. The aim of this study was to investigate whether dermatitis could be induced in patients with atopic dermatitis by inhalation of house dust mite.
Twenty patients with atopic dermatitis underwent bronchial provocations with house dust mite. Challenge tests were performed with four concentrations of a standardized house dust mite extract in a double-blind, randomized, placebo-controlled fashion. Spirometry was performed, and FEV1 was measured before and after each challenge dose. Changes in severity or localization of itching or erythema were recorded.
In nine of 20 patients with atopic dermatitis bronchial challenge with house dust mite induced unequivocal skin symptoms after 1.5 to 17 hours. Pruritic erythematous lesions on noninvolved sites together with exacerbations of existing lesions were seen in three patients. Three patients had an exacerbation only, and three other patients had new lesions only. In eight of nine patients with house dust mite inhalation-induced dermatitis, skin symptoms were preceded by an early bronchial reaction. All patients with house dust mite-induced dermatitis had a history of asthma, and as a group they had a higher mean blood total IgE level compared with the "negative skin responders." One patient had pruritic erythema on the placebo challenge day, without a preceding bronchoconstrictive reaction. The number of patients who had a skin response on the house dust mite challenge day was significantly higher than the number of patients who had a skin response on the placebo day (p = 0.011 [Prescott's test]).
The respiratory route may be relevant in the induction and exacerbation of dermatitis in a subset of patients with atopic dermatitis who have early bronchial reactions after house dust mite inhalation, a history of asthma, and an elevated blood total IgE level. Furthermore, these findings suggest a possible causal relationship between bronchial reactions and skin reactions.
屋尘螨在特应性皮炎发病机制中的作用仍存在争议。近期研究表明，屋尘螨变应原与预先处理过的皮肤进行密集的表皮接触可能诱发皮炎。然而，在与屋尘螨自然接触过程中是否满足这些条件尚不确定。过去曾有人提出吸入变应原可诱发特应性皮炎病情加重。本研究的目的是调查吸入屋尘螨是否会在特应性皮炎患者中诱发皮炎。
20例特应性皮炎患者接受了屋尘螨支气管激发试验。采用四种浓度的标准化屋尘螨提取物，以双盲、随机、安慰剂对照的方式进行激发试验。进行肺量测定，并在每次激发剂量前后测量第一秒用力呼气量（FEV1）。记录瘙痒或红斑严重程度或部位的变化。
20例特应性皮炎患者中有9例在吸入屋尘螨支气管激发试验后1.5至17小时出现明确的皮肤症状。3例患者在未受累部位出现瘙痒性红斑性病变，同时现有病变加重。3例患者仅病情加重，另外3例患者仅出现新病变。在9例因吸入屋尘螨诱发皮炎的患者中，有8例患者的皮肤症状之前出现了早期支气管反应。所有因屋尘螨诱发皮炎的患者都有哮喘病史，并且作为一个群体，他们的平均血液总IgE水平高于“皮肤反应阴性者”。1例患者在安慰剂激发试验日出现瘙痒性红斑，无先前的支气管收缩反应。在屋尘螨激发试验日出现皮肤反应的患者数量显著高于在安慰剂日出现皮肤反应的患者数量（p = 0.011[普雷斯科特检验]）。
对于一部分特应性皮炎患者，其在吸入屋尘螨后出现早期支气管反应、有哮喘病史且血液总IgE水平升高，呼吸道途径可能与皮炎的诱发和加重有关。此外，这些发现提示支气管反应与皮肤反应之间可能存在因果关系。
