Usmani N, Wilkinson S M
Dermatology Department, Leeds Teaching Hospitals, Great George Street, Leeds, UK.
Clin Exp Allergy. 2007 Oct;37(10):1541-6. doi: 10.1111/j.1365-2222.2007.02805.x.
In our clinic we routinely patch test patients referred from occupational health for the investigation of latex contact urticaria. We also undertake both patch and prick testing (where indicated) in patients referred with persistent dermatitis/eczema. If investigation of allergic skin disease is undertaken by a non-dermatologist, it is unlikely that patch testing will be performed.
To carry out a retrospective analysis of patients who had been prick tested to establish whether an incomplete diagnosis would have been reached if patch testing had been omitted.
Details of patients who had attended for patch testing between July 2004 and December 2005 were analysed. Patients who had had prick tests and patch testing were identified. The outcomes of prick tests and patch testing were documented together with the clinical relevance.
Three hundred and thirty out of 1060 patients referred to the clinic were prick tested. 54.2% patients were referred from dermatologists. 26.6% were referred from occupational health, 68 patients had positive reactions on prick testing of whom 36 had positive patch tests (52.9%), which were of current relevance in 27 patients (39.7%). Nine out of 106 health workers referred to exclude latex contact urticaria had positive prick tests to latex. Fifty of these patients demonstrated delayed-type hypersensitivity with nickel, cobalt, rubber and its additives being the most common allergens found. Of the 262 patients who had negative prick tests, 121 had positive patch tests (46.1%) of current relevance to patient history in 92 subjects (35.1%). While none of the six patients referred for investigation of reaction to local anaesthetics had a positive prick test, one was allergic to local anaesthetic on patch testing.
Omission of patch testing from the investigation of allergic skin disease, even when contact urticaria may be the sole suspected diagnosis, would result in the frequent missed diagnosis of contact allergy. We recommend that patients with suspected allergic skin disease are investigated in an environment where investigation of both immediate- and delayed-type hypersensitivity can be undertaken. In particular, patients with atopic eczema, suspected latex rubber allergy, hand dermatitis (particularly occupational) and drug reactions should be targeted to receive both investigations.
在我们的诊所，我们常规对职业健康转诊来的患者进行斑贴试验，以调查乳胶接触性荨麻疹。对于因持续性皮炎/湿疹转诊来的患者，我们也会在必要时进行斑贴试验和点刺试验。如果由非皮肤科医生对过敏性皮肤病进行调查，不太可能会进行斑贴试验。
对接受点刺试验的患者进行回顾性分析，以确定如果省略斑贴试验是否会导致诊断不完整。
分析2004年7月至2005年12月期间前来进行斑贴试验的患者的详细信息。确定接受了点刺试验和斑贴试验的患者。记录点刺试验和斑贴试验的结果以及临床相关性。
转诊至该诊所的1060名患者中有330名接受了点刺试验。54.2%的患者由皮肤科医生转诊。26.6%由职业健康部门转诊，68名患者点刺试验呈阳性，其中36名斑贴试验呈阳性（52.9%），27名患者（39.7%）的结果与当前情况相关。转诊以排除乳胶接触性荨麻疹的106名医护人员中有9名对乳胶点刺试验呈阳性。这些患者中有50名表现出迟发型超敏反应，镍、钴、橡胶及其添加剂是最常见的变应原。在262名点刺试验阴性的患者中，121名斑贴试验呈阳性（46.1%），92名受试者（35.1%）的结果与患者病史当前相关。在转诊来调查局部麻醉药反应的6名患者中，无人点刺试验呈阳性，但有1人斑贴试验对局部麻醉药过敏。
即使接触性荨麻疹可能是唯一怀疑的诊断，在过敏性皮肤病调查中省略斑贴试验也会导致接触性过敏的诊断经常漏诊。我们建议，在能够同时进行速发型和迟发型超敏反应调查的环境中对疑似过敏性皮肤病患者进行调查。特别是，特应性皮炎、疑似乳胶橡胶过敏、手部皮炎（尤其是职业性）和药物反应的患者应接受这两种检查。
