接触性皮炎是否真与硫柳汞无关

最近，许多研究者声称硫柳汞是筛查接触性皮炎中最无关的一种过敏原。在本诊所对508例疑似接触性过敏性皮炎的患者进行了斑贴试验。同时对他们进行包括医学、人口统计学和职业内容的问卷调查。应用标准化学技术诊断方法（Malmo，Sweden）和其他病例相关的辅助系列检查。对硫柳汞发生过敏反应的相关性评分为1～6。19例（3．7％）对硫柳汞发生过敏反应，其中6例（31．5％）有明确相关性，8例（42．1％）可能相关，仅3例（15．8％）为无关反应。     

Gastroduodenal mucosal hemodynamics by endoscopic reflectance spectrophotometry

The reflectance spectrophotometric technique measures an index of mucosal hemoglobin concentration and an index of oxygen saturation by spectral analysis of light reflected from the mucosal surface. Using a commercially available unit, a technique for obtaining reproducible endoscopic measurements with acceptable intraobserver and interobserver variability was developed in the anesthetized dogs. The reflectance spectrophotometric finding that experimentally induced prehepatic portal hypertension did not affect gastric mucosal blood flow was confirmed by hydrogen gas clearance measurements. Endoscopic studies in patients with active duodenal ulcer disease revealed a higher index of mucosal hemoglobin concentration and a normal index of oxygen saturation (i.e., an increase in blood flow) at the margin of the ulcer compared with the adjacent normal appearing mucosa.     

Thimerosal – Is it really irrelevant?

Recently, several investigators claimed that thimerosal is one of the most irrelevant allergens existing in screening for contact dermatitis. 508 patients who were suspected to have allergic contact dermatitis were patch tested at our clinic. They completed a questionnaire including medical, demographic and occupational details. We used the standard tray of chemotechnique diagnostics (Malmö, Sweden) and additional series, which were case relevant. The relevance of the allergic reaction to thimerosal was scored from 1 to 6. 19 patients (3.7%) had an allergic reaction to thimerosal. 6 (31.5%) had a definite relevance and 8 (42.1%) had a probable relevance. Only 3 patients (15.8%) had an irrelevant reaction. SPIN value (significance–prevalence index number) was 2281. We found a high proportion of mechanics (42.1%) among the patients who had positive reaction to thimerosal (P < 0.0001). Although previous reports found thimerosal highly irrelevant, our daily experience being supported by the above data indicates that positive reactions to thimerosal could be relevant for many patients.     

Value of preemployment medical assessments for white-collar workers

Employee absenteeism as a result of illness, as well as the need to enhance worker efficiency, are areas of increasing concern to employers. Given that preemployment medical assessments are expensive, the authors believe it is prudent to evaluate the cost-effectiveness of such procedures. Medical literature was reviewed, and relevant studies on preemployment assessments were analyzed in terms of yield and methodology. The authors found no clear guidelines for preemployment medical evaluations for white-collar applicants, who typically work in low-risk environments; however, they did conclude that laboratory testing and imaging methods are likely overused. Clear criteria should exist for medical assessment of job applicants, with an emphasis on cost-effectiveness. On the basis of recommendations contained in the literature, the authors suggest use of a self-administered questionnaire, with evaluation by an occupational health staff member when necessary, as the method(s) of choice for preemployment assessment of white-collar workers.     

The additive value of patch testing with patients' own products at an occupational dermatology clinic

Background and objectives: Patch testing with commercially available kits detects only 70–80% of relevant allergens in patients with contact dermatitis. This is not ideal, especially when occupational issues are being evaluated. This study analyses our data regarding reactions to patients' own products.
Methods: In a 5-year period, 1532 patients were assessed in our occupational dermatology clinic.
Results: We found that 101 patients (6.6%) reacted to their own samples. In 20 (1.3%) cases, reacting to their own samples was the only clue for detecting the responsible allergen. In 59 (3.9%) cases, testing with their own samples reinforced their reactions to commercial allergens.
Conclusions: We found the overall additive value of testing with patients' own products to be 5.2%. This is not a low proportion considering the 20–30% false negative rate when patch testing. Patch testing with patients' own samples, appropriately diluted should be undertaken whenever possible.     

The human skin/chick chorioallantoic membrane model accurately predicts the potency of cosmetic allergens

Abstract:  The current standard method for predicting contact allergenicity is the murine local lymph node assay (LLNA). Public objection to the use of animals in testing of cosmetics makes the development of a system that does not use sentient animals highly desirable. The chorioallantoic membrane (CAM) of the chick egg has been extensively used for the growth of normal and transformed mammalian tissues. The CAM is not innervated, and embryos are sacrificed before the development of pain perception. The aim of this study was to determine whether the sensitization phase of contact dermatitis to known cosmetic allergens can be quantified using CAM-engrafted human skin and how these results compare with published EC3 data obtained with the LLNA. We studied six common molecules used in allergen testing and quantified migration of epidermal Langerhans cells (LC) as a measure of their allergic potency. All agents with known allergic potential induced statistically significant migration of LC. The data obtained correlated well with published data for these allergens generated using the LLNA test. The human-skin CAM model therefore has great potential as an inexpensive, non-radioactive, in vivo alternative to the LLNA, which does not require the use of sentient animals. In addition, this system has the advantage of testing the allergic response of human, rather than animal skin.