Department of Dermatology and Allergy Centre, Odense University Hospital, University of Southern Denmark, Odense, Denmark.
Contact Dermatitis. 2013 Feb;68(2):94-7. doi: 10.1111/cod.12004.
Background. Two readings of patch test reactions are recommended. Objectives. To evaluate the outcome of a second patch test reading of TRUE Test® allergens on D6/7 in relation to negative or doubtful reactions on D3/4. Methods. This was a retrospective investigation of patch test data from January 1992 to October 2011 from consecutive eczema patients tested with the TRUE Test® panels. Results. In the period of nearly 20 years, a total of 9997 patients were tested. The total number of positive reactions to the 29 allergens was 6509; 4.4% were positive on D6/7 and negative on D3/4; and 9.1% were positive on D6/7 after a doubtful (?+) reaction on D3/4. Neomycin was the most frequent allergen giving delayed positive reactions (57%), followed by budesonide (42%) and hydrocortisone-17-butyrate (31%). Conclusion. A total of 4.4% of positive TRUE Test® reactions would be missed, and 9.1% might be missed, if only one reading was performed on D3/4. The results emphasize that many doubtful reactions at D3/4 may develop into positive reactions at a later reading. This may have important implications for evaluation of the clinical relevance of the test result.
背景。推荐对斑贴试验反应进行两次读数。目的。评估 TRUE Test®过敏原在 D6/7 上的第二次斑贴试验读数与 D3/4 上的阴性或可疑反应之间的结果。方法。这是对 1992 年 1 月至 2011 年 10 月连续接受 TRUE Test®斑贴试验的湿疹患者的斑贴试验数据进行的回顾性调查。结果。在将近 20 年的时间里，共有 9997 名患者接受了测试。29 种过敏原的总阳性反应数为 6509 个；4.4%的患者在 D6/7 上呈阳性，在 D3/4 上呈阴性；在 D3/4 上呈可疑（+）反应后，9.1%的患者在 D6/7 上呈阳性。新霉素是最常引起迟发性阳性反应的过敏原（57%），其次是布地奈德（42%）和氢化可的松-17-丁酸酯（31%）。结论。如果仅在 D3/4 上进行一次读数，将错过 TRUE Test®反应的 4.4%阳性反应，而 9.1%的阳性反应可能会被错过。结果强调，D3/4 上的许多可疑反应可能在以后的读数中发展为阳性反应。这对于评估试验结果的临床相关性可能具有重要意义。
