Rodríguez Edna, Valbuena Martha Cecilia, Rey Maritza, Porras de Quintana Luisa
Centro Dermatológico Federico Lleras Acosta, ESE Bogota, Colombia.
Photodermatol Photoimmunol Photomed. 2006 Aug;22(4):189-92. doi: 10.1111/j.1600-0781.2006.00212.x.
To describe and identify the photoallergens causing photoallergic contact dermatitis in the population attending the outpatient clinic of the Centro Dermatologico Federico Lleras Acosta (CDFLLA), the National Institute of Dermatology of Colombia.
Eighty-two patients with clinical diagnosis of photoallergic contact dermatitis enter the study. These patients attended the CDFLLA between August 2001 and May 2003. Photopatch tests were performed using the standard series of sunscreens (Chemotechnique Diagnostics) and 6-methylcoumarin. Cetyl alcohol, phenoxyethanol, methylparabene, propylene glycol, triethanolamine, propylparabene, trichlorocarbanilide and dichromate were also included. The allergens were applied in duplicate on the healthy skin of the back and covered with opaque tape withdrawn 24 h later, the panel on the right was irradiated with an ultraviolet A dose of 5 J/cm(2). The tests were read 24 h after the application of the allergens, 24 and 72 h post-irradiation. The readings were assessed according to the visual scoring system recommended by the International Contact Dermatitis Research Group.
Twenty-six patients (31.7%) showed positive photopatch test responses to one or several allergens. Four of them showed positive results to three components of the series and four patients to two components. Thirty-eight photoallergic and 18 allergic reactions were observed. Ultraviolet filters were the substances which more frequently produced positive photopatch test responses (30.5%). The most common ultraviolet filter photoallergen was benzophenone-3 with 22/82 positive results (26.8%), followed by octyl methoxycinnamate (8/82), benzophenone-4 and mexenone (2/82), phenylbenzimidazole sulphonic acid, methylbenziliden camphor and octyl dimethyl PABA (1/82). One patient showed a photoallergic response to 6-methylcoumarin. There was a concordance between the allergen which elicited the positive response and the use of different substances which contained that molecule among its compounds in 17 patients (65.3%). 19.5% of the patients (16/82) showed positive results to one or several allergens in the irradiated panel as well as in the unirradiated control site. These cases were diagnosed as contact allergy, probably caused by aeroallergens, presenting a natural history and a clinical picture similar to photocontact allergy. The most common allergen was dichromate with 10 positive results.
The results of this study confirm that sunscreens are the more frequently involved substances in photoallergic contact dermatitis in our population. Identification of the photoallergen is the key element for adequate disease control and patient education.
描述并确定在哥伦比亚国家皮肤病研究所费德里科·耶拉斯·阿科斯塔皮肤病中心（CDFLLA）门诊就诊人群中引起光变应性接触性皮炎的光变应原。
82例临床诊断为光变应性接触性皮炎的患者进入本研究。这些患者于2００1年8月至2００3年5月在CDFLLA就诊。使用标准系列防晒剂（Chemotechnique Diagnostics公司产品）和6-甲基香豆素进行光斑贴试验。还包括十六醇、苯氧乙醇、对羟基苯甲酸甲酯、丙二醇、三乙醇胺、对羟基苯甲酸丙酯、三氯卡班和重铬酸盐。将变应原重复涂于背部健康皮肤上，用不透明胶带覆盖，24小时后去除，右侧试验区用5 J/cm(2)的紫外线A照射。在变应原涂抹后24小时、照射后24小时和72小时进行试验读数。根据国际接触性皮炎研究组推荐的视觉评分系统进行读数评估。
26例患者（31.7%）对一种或几种变应原光斑贴试验呈阳性反应。其中4例对该系列的3种成分呈阳性结果，4例对2种成分呈阳性结果。观察到38例光变应性反应和18例变应性反应。紫外线滤过剂是最常引起光斑贴试验阳性反应的物质（30.5%）。最常见的紫外线滤过剂光变应原是二苯甲酰甲烷，22/82呈阳性结果（26.8%），其次是桂皮酸盐（8/82）、二苯甲酰甲烷和甲氧基肉桂酸辛酯（2/82）、苯基苯并咪唑磺酸、甲基亚苄基樟脑和二甲基对氨基苯甲酸辛酯（1/82）。1例患者对6-甲基香豆素呈光变应性反应。在17例患者（65.3%）中，引起阳性反应的变应原与化合物中含有该分子的不同物质的使用之间存在一致性。19.5%的患者（16/82）在照射区和未照射对照部位对一种或几种变应原呈阳性结果。这些病例被诊断为接触性过敏，可能由气源性变应原引起，其自然病史和临床表现与光接触性过敏相似。最常见的变应原是重铬酸盐，有10例呈阳性结果。
本研究结果证实，防晒剂是我国人群光变应性接触性皮炎中最常涉及的物质。确定光变应原是疾病适当控制和患者教育的关键因素。
