Department of Dermatology, Dr. Ram Manohar Lohia Hospital, New Delhi, India.
Indian J Dermatol Venereol Leprol. 2009 Sep-Oct;75(5):483-7. doi: 10.4103/0378-6323.55391.
Photodermatitis is an abnormal response to ultraviolet radiation (UVR). The photoallergic contact dermatitis caused by plant allergens is a serious cause of morbidity in India. Airborne contact dermatitis is the classical presentation of plant-induced dermatosis, which may become difficult to differentiate from chronic actinic dermatitis in chronic cases. The rapid growth of parthenium weed in India and its ill effects on the population make it important to detect all cases of parthenium sensitivity, which in some cases might simulate photodermatitis.
This study aims to detect the occurrence of plant sensitivity and photosensitivity in idiopathic-acquired photodermatoses, airborne contact dermatitis and general population taken as controls.
One hundred and fifty six consecutive patients suffering from polymorphic light eruption (PMLE), chronic actinic dermatitis (CAD) and airborne contact dermatitis (ABCD) were enrolled in the study over a period of three years (June 2004 to May 2007). An equal number of age and sex matched healthy subjects were enrolled in the study as controls. All the patients were subjected to detailed history taking, clinical examination and histopathological examination for diagnosis. Patch and photopatch testing were perfomed in all the patients and healthy controls for detection of allergic and photoallergic reactions to parthenium, xanthium and chrysanthemum plant antigens and control antigens.
Out of 156 patients enrolled in the study, 78 (50%) had CAD, 67 (42.9%) had PMLE and 11 (7.05%) had ABCD. The occurrence of parthenium/xanthium allergy and photoallergy, either to parthenium or both was most commonly found in ABCD (72.7%), followed by CAD (32%). In PMLE 4.5% cases showed photoallergy. Only 1.9% in the control group showed sensitivity to parthenium and xanthium.
This study indicates that parthenium (and possibly xanthium) may act as important environmental factors in the initiation and perpetuation of not only ABCD but of CAD as well. Photoexacerbation to UVA at positive parthenium/xanthium sensitivity sites in ABCD and CAD indicates that ABCD with photosensitivity to compositae can lead to CAD.
光皮病是一种对紫外线（UVR）的异常反应。植物过敏原引起的光变应性接触性皮炎是印度发病率较高的严重原因。空气传播性接触性皮炎是植物性皮肤病的经典表现，在慢性病例中，它可能变得难以与慢性光化性皮炎区分。豚草在印度的迅速生长及其对人口的不良影响使得检测所有豚草过敏病例变得非常重要，在某些情况下，这些病例可能模拟光皮病。
本研究旨在检测特发性获得性光皮病、空气传播性接触性皮炎和作为对照的一般人群中植物敏感性和光敏感性的发生情况。
在三年的时间内（2004 年 6 月至 2007 年 5 月），我们连续招募了 156 名患有多形性光疹（PMLE）、慢性光化性皮炎（CAD）和空气传播性接触性皮炎（ABCD）的患者。作为对照，我们招募了相同年龄和性别的 156 名健康受试者。对所有患者进行详细的病史采集、临床检查和组织病理学检查以进行诊断。对所有患者和健康对照进行斑贴和光斑贴试验，以检测对豚草、苍耳和菊花植物抗原及对照抗原的过敏和光过敏反应。
在纳入研究的 156 名患者中，78 名（50%）患有 CAD，67 名（42.9%）患有 PMLE，11 名（7.05%）患有 ABCD。在 ABCD 中最常见的是出现豚草/苍耳过敏和光过敏，要么对豚草过敏，要么两者都过敏（72.7%），其次是 CAD（32%）。在 PMLE 中，4.5%的病例出现光过敏。对照组中只有 1.9%的人对豚草和苍耳敏感。
本研究表明，豚草（可能还有苍耳）可能是不仅 ABCD 而且 CAD 发病和持续的重要环境因素。在 ABCD 和 CAD 中，对阳性豚草/苍耳敏感性部位进行光增强 UVA 照射表明，对菊科植物有光敏感性的 ABCD 可能导致 CAD。
