False-positive, follicular and irritant patch teat reactions to metal salts

853 hard metal workers were patch tested with nickel sulphate 5%, potassium dichromate 0.5% and cobalt chloride 1%, each in petrolatum. Non-allergic reactions appeared in 6.5% of the nickel tests, 13% of the chromium tests and 18.3% of the cobalt tests. Most of the individuals with positive, poral or pustular reactions were retested with serial dilutions of metal salts in pet. and in water. The accuracy of a positive initial nickel reaction was 83%, a chromium reaction 40% and a cobalt reaction 62%. The nonallergic reactions were partly reproducible and correlated with both the type of patch test material and with individual factors. Weak and moderately strong positive patch test reactions to metal salts may be irritant and should be checked with serial dilution tests or at least be retested. A reduction of the cobalt chloride concentration from 1% to 0.5% in the standard test material is discussed.     

Influence of topical metal binding substances, vehicles, and corticosteroid creams on the allergic patch test reaction in metal-sensitive patients

Persons known to be allergic to nickel, cobalt, or both were patch tested with serial dilutions of cobalt chloride or nickel sulfate either in petrolatum on skin treated with topical preparations with and without metal-binding compounds or incorporated into such special preparations. A decreased response was found in patients tested with Vioform (clinquinol) and cobalt chloride simultaneously, whereas rutin (3,3',4',5,7-pentahydroxyflavon 3-rhamnoglucosid) increased the response, and polyfloretin phosphate had no effect. The vehicles proved significant: "Ung Merck" and "W/O Cream Base" increased reactivity, whereas polyethylene glycol gave good protection against metal ions. As expected, corticosteroid creams suppressed the inflammatory response.     

Effects of topical corticosteroid and tacrolimus on ceramides and irritancy to sodium lauryl sulphate in healthy skin

The skin barrier, located in the stratum corneum, is influenced mainly by the lipid and protein composition of this layer. In eczematous diseases impairment of the skin barrier is thought to be of prime importance. Topical anti-inflammatory drugs and emollients are the most widely used eczema treatments. The aim of this study was to examine the effects of topically applied corticosteroid, tacrolimus and emollient on stratum corneum lipids and barrier parameters. Nineteen healthy volunteers participated in the study. Both forearms of the subjects were divided into four areas, which were treated twice daily for one week with betamethasone, tacrolimus, emollient, or left untreated, respectively. After one week each area was challenged with a 24 h sodium lauryl sulphate patch test. The lipids were collected using the cyanoacrylate method and evaluated by high performance thin layer chromatography. For evaluation of the skin barrier, transepidermal water loss, erythema and electrical capacitance were measured. The ceramide/cholesterol ratio was increased in betamethasone- (p?=?0.008) and tacrolimus-treated (p?=?0.025) skin compared with emollient-treated skin. No differences in ceramide subgroups were found between treatment regimes. Pretreatment with betamethasone (p?=?0.01) or with tacrolimus (p?=?0.001) causes a decreased inflammatory response to sodium lauryl sulphate compared with emollient. In conclusion, treatment with betamethasone and tacrolimus has a positive effect on the ceramide/cholesterol ratio and susceptibility to irritant reaction compared with an emollient.     

The spontaneous regression of palmoplantar pustulosis following removal of dental amalgams: A report of two cases

Metal allergens are occasionally reported to be associated with palmoplantar pustulosis. We describe two severe, therapy‐resistant, chronic cases of palmoplantar pustulosis induced by metal dental fillings. Both patients' clinical findings and symptoms regressed following the removal of their metal teeth. A patch test examination revealed positive reactions to metal allergens in both cases (in Case 1 the positive reactions were to cobalt chloride hexahydrate and nickel sulfate and in Case 2 the positive reaction was to nickel sulphate). Our studies suggest that metal allergens may play an important role in the pathogenesis of palmoplantar pustulosis.     

Cobalt allergy in hard metal workers

Hard metal contains about 10% cobalt. 853 hard metal workers were examined and patch tested with substances from their environment. Initial patch tests with 1% cobalt chloride showed 62 positive reactions. By means of secondary serial dilution tests, allergic reactions to cobalt were reproduced in 9 men and 30 women. Weak reactions could not normally be reproduced. A history of hand eczema was found in 36 of the 39 individuals with reproducible positive test reactions to cobalt, while 21 of 23 with a positive initial patch test but negative serial dilution test had never had any skin problems. Hand etching and hand grinding, mainly female activities and traumatic to the hands, were found to involve the greatest risk of cobalt sensitization. 24 individuals had an isolated cobalt allergy. They had probably been sensitized by hard metal work, while the individuals, all women, who had simultaneous nickel allergy had probably been sensitized to nickel before their employment and then became sensitized to cobalt by hard metal work. A traumatic occupation, which causes irritant contact dermatitis and/or a previous contact allergy or atopy is probably a prerequisite for the development of cobalt allergy.     

The development of metal hypersensitivity in patients with metal-to-plastic hip arthroplasties

Sixty-six patients who had to undergo total hip replacement by means of a metal-to-plastic Stanmore prosthesis, were patch-tested prior to and 6 to 12 months after surgery with the standard ICDRG all allergens series and with acrylic monomer 5% in acetone. In 62 patients the history of metal allergy as well as the patch tests to all tested allergens were negative. One patient with a history of metal allergy reacted negatively before surgery; about 6 months after surgery the patch test to nickel sulphate was positive (2 plus). Three other patients developed positive patch test reaction after surgery: two reacted positively to nickel sulphate (2 plus) and one to cobalt chloride (2 plus). In none of the 66 patients have local side effects of the prostheses been found to date.     

The effect of aqueous cream BP on the skin barrier in volunteers with a previous history of atopic dermatitis

Background The emollient aqueous cream BP is frequently used for the treatment of atopic dermatitis (AD), yet it is associated with a high rate of adverse cutaneous reactions. It contains the harsh anionic surfactant sodium lauryl sulphate, a known negative environmental factor associated with the exacerbation of AD. Objectives To investigate the effect of aqueous cream BP on stratum corneum (SC) integrity and skin barrier function in volunteers with a predisposition to a defective skin barrier. Methods Thirteen volunteers with a previous history of AD (no symptoms for 6 months) applied aqueous cream BP twice daily to the volar side of one forearm for 4 weeks. The other forearm was left untreated as a control. Permeability barrier function and SC integrity were determined before and after treatment by measuring transepidermal water loss (TEWL) in conjunction with tape‐stripping. For comparison, 13 volunteers with current AD were recruited for assessment, without treatment, of SC integrity and skin barrier function at unaffected sites. Results Topical application of aqueous cream BP resulted in significant elevation of baseline TEWL and a concomitant decrease in SC integrity. Measurements made after no treatment in volunteers with current AD, at unaffected sites, suggest that application of aqueous cream BP negatively affects the skin barrier towards the damaged state associated with onset of flares of the disease. Conclusions Aqueous cream BP used as a leave‐on emollient caused severe damage to the skin barrier in volunteers with a previous history of AD. Aqueous cream BP should not be used as a leave‐on emollient in patients with AD.     

Contact allergy in male construction workers in Sao Paulo, Brazil, 2000-2005

There are no recent data on allergens in the construction industry in Brazil; apparently there were no changes in allergenic substances. The objective of this study was to identify sensitization to allergens in adult males working in the construction industry. A cross-sectional study with adult males submitted to patch tests from May 2000 to December 2005. Out of 169 male patients, 83 were construction workers. The five most frequent allergens among the construction workers were potassium dichromate (57%), carba-mix (34.9%), cobalt chloride (30.2%), thiuram-mix (27.9%) and neomycin (19.8%). There is a significant sensitization to potassium dichromate, cobalt, carba-mix, and thiuram-mix, demonstrating that cement and rubber gloves of personal protection equipment still account for allergic contact dermatitis in construction industry workers.     

HLA -A, -B, -C and -DR antigens in individuals with sensitivity to cobalt

In a skin investigation of 853 individuals working with hard metal manufacturing 39 cases of cobalt allergy were found. Thirty-five of the individuals with cobalt sensitivity and 102 matched controls were HLA-A, -B, -C and -DR typed. No significantly deviating HLA antigen frequencies were observed when the two groups were compared. Thus, there are no signs that a certain HLA antigen would dispose to cobalt allergy. In the cobalt sensitive group the B7 positive individuals showed particularly often simultaneous reactions to other contact allergens (p = less than 0.025). The B12 positive individuals had low reactivity (p = less than 0.0001) while the A28 positive showed high reactivity (p = less than 0.015).     

Epicutaneous testing with a standard series. Results in 12,026 patients

From 1977 to 1983, 12,026 patients were given patch tests with a standard series of substances. A total of 4,494 (37.4%) had positive patch-test reactions to one or more allergens; the average number of positive reactions was 1.85. The most frequent reactions were due to nickel sulphate (positive reactions in 9.2% of those tested), fragrance mix (8.9%), balsam of Peru (6.3%), cobalt chloride (4.7%), potassium dichromate (4.3%) and wool alcohols (4.3%). Women showed significantly more positive reactions than men to nickel sulphate, cobalt chloride, wool alcohols, and parabens and significantly fewer positive reactions than men to potassium dichromate, PPD mix, and epoxy resin. Younger patients showed significant more positive reactions to nickel sulphate and cobalt chloride; middle-aged patients reacted more to potassium dichromate, paraphenylendiamine, formaldehyde and thiuram mix; elderly patients reacted to balsam of Peru, wool alcohols, caine mix, neomycin sulfate, benzocaine, colophony, clioquinol, mafenide, parabens, and gentamycin sulfate.     

Measurement of cutaneous inflammatory reactions using a scanning laser-Doppler velocimeter

The performance of a new scanning laser-Doppler velocimeter (LDV), which can rapidly measure blood flux over a large area of skin without contact with the skin surface, was compared with that of a conventional laser-Doppler instrument. The vascular response was measured to a range of doses of UVB, and dilutions of contact allergens and sodium lauryl sulphate. The detection threshold of the scanning LDV was equal to, or lower than, that of the conventional instrument. For allergic contact hypersensitivity reactions (ACH), the coefficient of variation was significantly less using the scanning LDV. The scanning LDV allowed accurate measurement of the change in area that occurs with increasing intensity of inflammatory reaction. For ACH reactions the area of inflammation continued to increase at dilutions where blood flux had reached a plateau. The flare area was found to increase linearly with log dose of histamine with no change in blood flux.     

Patch testing in cases of eczema and dermatitis in Beijing, China

Of 124 patients with eczema and dermatitis patch tested by the European standard series of allergens in the period Horn April to October 1989, 59 cases showed sensitivity to 1 or more allergens, Potassium dichromate, nickel sulphate and cobalt chloride were the 3 major sensitizers with a frequency of 17.9%. 13.8% and 10.6%, respectively. The office and factory workers showed higher incidence of positive reactions than the student group. The environment of the office and the factory seems to be the potential Source of exacerbating factors of eczematous skin disease.     

Cobalt-containing alloys and their ability to release cobalt and cause dermatitis

Background:  Cobalt, nickel, and chromium are important skin sensitizers. However, knowledge about cobalt exposure and causes of cobalt sensitization is limited.
Objectives:  To study release of cobalt, nickel, and chromium from some cobalt-containing hard metal alloys and to test reactivity to the materials in cobalt-sensitized patients.
Methods:  Discs suitable for patch testing were made of some hard metal alloys. Cobalt, nickel, and chromium release from the materials was determined by immersion in artificial sweat (2 min, 1 hr, 1 day, and 1 week). Patch test reactivity to the discs and to serial dilutions of cobalt and nickel was assessed in previously patch-tested dermatitis patients (19 cobalt positive and 18 cobalt-negative controls).
Results:  All discs released cobalt, nickel, and chromium. Some discs released large amounts of cobalt (highest concentration: 290 μg/cm²/week). Seven discs elicited three or more positive test reactions.
Conclusions:  The concentration of released cobalt was high enough to elicit allergic contact dermatitis in cobalt-sensitized patients. As the materials in the discs are used in wear parts of hard metal tools, individuals with contact allergy to cobalt may develop hand eczema when handling such materials.     

Effect of long-term use of moisturizer on skin hydration, barrier function and susceptibility to irritants

Moisturizers are often used in the prevention and treatment of irritant contact dermatitis. The present study was to determine whether long-term daily use of a moisturizer on normal skin would affect skin barrier function, hydration state, or susceptibility to sodium lauryl sulphate. Healthy volunteers used a moisturizer on one forearm 3 times daily for 4 weeks. The other forearm served as a control. Afterwards both forearms were challenged with a patch-test of sodium lauryl sulphate. Skin barrier function was evaluated by measuring trans-epidermal water loss and skin hydration by measuring electrical capacitance. Electrical capacitance was significantly increased on the treated arm during the treatment period. After challenge with sodium lauryl sulphate, transepidermal water loss was significantly higher on the arm treated with moisturizer than on the control arm. The results suggest that long-term treatment with moisturizers on normal skin may increase skin susceptibility to irritants.     

In vitro testing for cobalt sensitivity: an aid to diagnosis

Peripheral blood lymphocytes from 45 patients with a positive patch test to cobalt chloride (CoCl2) and 37 controls were stimulated with various concentrations of CoCl2 and/or cobalt sulphate (CoSO4) or cobalt nitrate (Co(NO3)2) or cobalt acetate [CH3COO)2Co) for various days in culture. Lymphocytes from 35 of these patients showed a significantly greater response than that of the controls. The response occurred in the T enriched population and was monocyte dependent. The strength of the in vivo serial dilution test results did not correlate well with the height of in vitro responses. Lymphocytes from 3 nickel and/or chromium sensitive patients failed to respond to stimulation with cobalt compounds thus confirming the specificity of the reaction. The DNA synthesis test seems to be a reliable in vitro method to aid in the diagnosis of cobalt sensitivity.     

Occupational airborne allergic contact dermatitis from methacrylates in a dental nurse

BACKGROUND: There are very few reports of airborne allergic contact dermatitis from methacrylates. OBJECTIVES: To report a dental nurse with facial eczema supposedly caused by airborne methacrylates present in the work environment. METHODS: Patch testing with serial dilutions of several methacrylates and work provocations in environments containing methacrylates was performed. RESULTS: Patch testing with serial dilutions of several methacrylates disclosed a high patch test reactivity. Repeated provocations when working with methacrylates resulted in facial eczema that resolved out of work. Attempts to collect the sensitizers using air pumps for the collection of vapors and filters for the collection of air-born aerosols failed. CONCLUSIONS: The clinical presentation was that of a facial dermatitis due to airborne exposure to methacrylates. It seems likely that 1 or several of these allergens caused the dermatitis.     

Reactive changes in the Langerhans' cells of human skin caused by occlusion with water and sodium lauryl sulphate

Human skin was patch tested with sodium lauryl sulphate or with water only for 48 h and biopsied immediately and after 24 h, then analyzed by immunocytochemistry and electron microscopy. Sodium lauryl sulphate produced a decrease in the number of epidermal Langerhans' cells and an increase in dermal Langerhans' cells, with individual variations. The 48-h water occlusion controls showed only slight reactions. Unexpectedly, quite pronounced reactive changes were seen 24 h after termination of water occlusion. Thus, dermal Langerhans' cells were commonly increased and epidermal Langerhans' cells tended to decrease in number. The results indicate that the 24-h interval is not a period of recovery but a period in which more pronounced reactive changes occur. Hydration over 48 h followed by dehydration leading to temporary damage to the epidermal barrier may explain the present findings. Some of the reactive changes observed after sodium lauryl sulphate exposure probably represent the additive effects of occlusion and sodium lauryl sulphate treatment.     

Combined effects of irritants and allergens. Synergistic effects of nickel and sodium lauryl sulfate in nickel- sensitized individuals

Knowledge of the combined effects of irritants and allergens is of interest with respect to accurate risk assessment. The threshold for elicitation of allergic contact dermatitis in previously sensitized individuals may theoretically be markedly influenced by the simultaneous presence of irritants and allergens. Combined exposures have, however, only been studied infrequently. In the present study, the combined effect of an irritant and an allergen was evaluated in a dose-response designed experimental study. 20 nickel-sensitized subjects were exposed to patch testing with varying concentrations of NiCl2 (nickel chloride) and sodium lauryl sulfate (SLS) alone and in combination. Evaluation of skin reactions was performed by colorimetry, measurement of transepidermal water loss and clinical evaluation, and the data were analyzed by logistic dose-response models. A synergistic effect was found of combined exposure to NiCl2 and SLS, as compared to each of the substances applied separately, as evaluated by colorimetry and clinical scoring. This means that the effect produced by the combined exposure was substantially greater than the effect produced by either of the substances alone. A synergistic effect of combined exposure on skin barrier impairment was not found, since the barrier function is significantly influenced by SLS-exposure only and not by NiCl2. Concentration limits are used by industry and government agencies to protect consumers. The present results clearly illustrate that elicitation thresholds and concentration limits may be influenced considerably by combined exposure to allergens and irritants.     

82例女性外阴慢性单纯性苔藓患者斑贴试验分析

目的：检测女性外阴慢性单纯性苔藓（VLSC）患者接触性过敏原情况。方法：对2017年3月至2018年3月就诊于我科的VLSC患者行60项变应原斑贴试验。结果：82例患者中53例患者(64.73%)呈阳性反应。60项变应原中共有29种变应原呈阳性反应，其中阳性率排前三位变应原种类为金属盐（32例）、防腐剂（18例）、芳香剂（16例），阳性率排前四位变应原分别为硫酸镍（24例）、氯化钴（15例）、芳樟醇氢过氧化物（10例）、甲基异噻唑啉酮（6例）。结论：VLSC可能与接触过敏原有关，金属盐、防腐剂、芳香剂是最常见变应原种类。     

Cross-reactivity between nickel and palladium demonstrated by systemic administration of nickel

Concomitant patch test reactions to nickel and palladium have frequently been reported in patients undergoing investigation because of suspected allergic contact dermatitis. Theoretically, these reactions can be explained by multiple, concomitant, simultaneous sensitization as well as cross-sensitization. We studied whether concomitant reactions to nickel and palladium could represent cross-sensitization in females hypersensitive to combinations of nickel, palladium and cobalt. Females were patch tested with serial dilutions of nickel sulfate, cobalt chloride and palladium chloride on the upper back. 1 month later, when the patch test reactions were gone, the patients were randomized into 2 groups that were challenged orally with either nickel or placebo. 1 day later, the areas of previous positive patch test reactions were read in a blind way looking for flare-up reactions. Nickel provocation but not placebo yielded flare-up reactions on sites previously tested with nickel (P = 0.012) and palladium (P = 0.006), but were also observed on sites previously tested with cobalt, even though this was not statistically significant. Flare-up reactions of previous patch test reactions to nickel and palladium after oral challenge with nickel speak in favour of a cross-reactivity mechanism.