Objective assessment of nickel sulfate patch test reactions with laser Doppler perfusion imaging

The laser Doppler perfusion scanning technique was used to assess the superficial blood flow of nickel sulfate hexahydrate patch test reactions. There was good agreement between laser Doppler and visual assessments when the highest assessment values of reactions were studied. Earlier detection of reactions was possible with the laser technique. There was great inter-individual variance in perfusion between identically tested patients. 4 patients were visually negative when a TRUE Test^TM patch test dose of 0.20 mg/cm² was applied for 48 h and the test area read 4× up to 168 h. These 4 showed a dose-related increase in perfusion and visually positive reactions using longer application times. The instrument allowed a dose reduction not possible for visual assessments. Reading transparent patches in contact with the skin through transparent semi-occlusive plastic foil or through windows in the tape strip over the patches, allowed us to detect perfusion at 48 h, where a longer application would have been needed using tape and visual assessments.     

The effect of topically applied corticosteroid on irritant and allergic patch test reactions

The purpose of the study was to assess the effect of topical corticosteroid on the patch test response in patients with known positive allergens and also to study any effect on the irritant response. In Study 1, 10 patients with known positive allergens had their backs pre-treated 2× daily for 3 days with either betamethasone dipropionate 0.5% or the equivalent ointment base. On day 4, previous known allergens and dilutions of sodium lauryl sulfate (5% and 10%) as an irritant were applied to each side of the back. In Study 2 (4 patients), a 1:4 dilution of betamethasone dipropionate was substituted for the full-strength preparation. Betamethasone dipropionate 0.05% caused total or partial suppression of the allergic reaction in 8 of in eases. The 1:4 dilution caused partial suppression in 3 cases. The irritant reaction was totally suppressed by betamethasone dipropionate in 1 of 10 cases and partially suppressed in 7 of 10. The 1:4 dilution decreased the intensity of the irritant reaction in 3 of 4 cases. The relevance of these results to clinical practice is discussed.     

Analysis of laser Doppler perfusion images of experimental irritant skin reactions

Background/aims: Laser Doppler perfusion imaging (LDPI) permits measurement of skin blood flow changes in patch test reactions. It is, as yet, unclear how collected data can best be handled and presented in order to maximize the possible discriminatory advantage of the imaging technique and to make the selection of data for statistical analysis as objective as possible. The aim of the present study was to compare a new software program (LDISOFT) for the analysis of LDPI images with the built-in standard statistical functions in the LDPI system (PIM 1.0). In addition, a modification of the software was used to gather additional data by performing sequential perfusion images. Methods: A dithranol cream was applied under Finn chambers for 30, 60 and 90 min on the ventral forearm skin of three volunteers. Photographic documentation and LDPI recordings were performed immediately after the removal of the Finn chambers and at 24, 48, 72 and 96 h. By the use of the above mentioned software, rectangular and threshold selected regions of interest were used to find an optimal way of calculating the mean perfusion and extent of the reactions. Results: An LDISOFT threshold of 2 V was adequate and showed agreement (r<0.902, n=78) between mean perfusion analysis performed by LDISOFT (threshold-steered region of interest) and LDPI statistics (rectangular region of interest). The LDISOFT program had the added advantage of comparing application-site size with reaction size. Sequential recordings showed both spatial and temporal perfusion variability. Conclusions: Utilization of the full potential of LDPI will involve optimization of data analysis and presentation. A more “automated” system for data analysis will reduce bias due to subjective selection of analysis area. Particularly in weaker reactions, in irregular shaped or ring reactions and when there is non-specific background irritation, this may represent an advantage. Averaging of sequential recordings reduced background noise.     

Histological distinction between early allergic and irritant patch test reactions: follicular spongiosis may be characteristic of early allergic contact dermatitis

Comparative light microscopic studies have revealed subtle differences between allergic and irritant reactions in the skin. In the search for specific differences, we focussed on the early inflammatory response. This pilot study was conducted to test the hypothesis that follicular spongiosis can differentiate between early allergic and irritant patch test reactions. 8 patients with known contact allergy to either colophony or quarternium-15 participated in the study. In each patient, allergic and irritant patch tests reactions were elicited, and 4-mm punch biopsies were taken after 6 8 h from clinically equipotent reactions. Paired sets of slides were assessed blindly by 2 pathologists. 1 patient showing a pityrosporum folliculitis was excluded from the study. All biopsies from allergic patch tests were characterized by follicular spongiosis, while biopsies from irritant patch tests showed no recognizable changes except a slight follicular spongiosis in 1 patient. The 2 pathologists agreed independently on the correct classification in 6 out of 7 cases (p=0.0156). We tested an optimized model, selecting non-irritant allergens and a well-known irritant. Further investigations are needed to elucidate the diagnostic significance of the histological classification of allergic and irritant cutaneous reactions in punch biopsies.     

Effect of test techniques of perfusion of neomycin sulfate patch tests. A comparative study with visual assessments

Effects of test techniques on neomycin patch test results have not been thoroughly investigated. This study focuses on effects of dose and application time of neomycin sulfate patch tests on test results. The effects are assessed both visually and by perfusion. 16 subjects positive to neomycin are retested with neomycin sulfate in various doses and vehicles applied with different application devices for variable time intervals. All subjects were tested with a serial-dose series for time intervals ranging from 3 to 96 h (4 days [D]). The results show very good agreement between perfusion assessments and positive and negative visual assessments of reactions; however, a gray zone was detected where reactions with variable perfusion were associated with visually questionable test responses. 1:27 serial dilutions and wide application time intervals show a positive response with perfusion assessments and partly with visual assessments. Regardless of reading technique, highest reactivity of reactions was detected at either 96 h (day [D] 4) or 168 h (D7) in each subject with minor exceptions, regardless of dose, vehicle, application device or application time. Some findings of the study support the idea that reactions with papules alone are positive tests. Possible effect of tapes and foils on test results are discussed.     

Phenotypic difference between allergic and irritant patch test reactions in man

Cellular responses in allergic and irritant contact dermatitis were analysed in situ using an immunohistochemical double staining technique with the aim of uncovering phenotypical differences of diagnostic importance. Allergic and irritant patch test reactions were elicited in 9 individuals using the Finn chamber technique. Thirty-nine skin biopsies from these reactions and from petrolatum controls were obtained 4 to 20 days after the test applications. Cell infiltrates were present throughout the observation period in both allergic and irritant reactions, but were usually greater in the former. In both types of reaction, anti-Leu 3a reactive cells predominated over anti-Leu 2a reactive cells. HLA-DR expression on keratinocytes was found in 9 of 14 allergic reactions, but not in irritant reactions or control areas. HLA-DQ antigens were not detected on keratinocytes. The presence of HLA-DR antigens on keratinocytes may reflect an immunological response of the allergic reactions, and thus be of diagnostic relevance.     

Allergic and irritant patch test reactions and atopic disease

This study presents a profile of patients with chronic recalcitrant eczematous disease referred by dermatologists for contact allergy evaluation. Allergic contact dermatitis (ACD) and irritant responses were carefully defined, as was the presence or absence of atopy obtained by history. Of 410 patients studied, 44% had no history of atopic disease and 46% were classed as definitely atopic. Among relevant ACD patch lest reactors ( n = 198). 51.5% had atopy, compared with 40.9% with no atopy but this difference was not significant. Likewise, among atopics ( n = 189). 54% had definite, relevant ACD patch test responses while 33.9% had negative ACD (again not significant). Significance was seen in the higher mean number of positive allergic patch tests in the atopic group (2.7 versus 2.0. p =0.0223). Irritant patch tests were highest among patients with both ACD and atopy ( p = U.0308) and the proportion of irritant responses correlated with increasing numbers of positive ACD tests. We conclude that atopics are at least as likely to have ACD as are non-u topics. Irritancy is increased in these patients with chronic dermatitis and the frequency of irritant reactions correlates with both greater numbers of ACD responses and with presence of atopy.     

Lymphocyte subsets and Langerhans cells in allergic and irritant patch test reactions: histometric studies

This study has attempted to distinguish between allergic and irritant reactions to patch tests by semiquantitative histological methods. The extent of perivascular chronic inflammatory infiltrate at 72 h in irritant patch test reactions to sodium lauryl sulphate was shown to be small and very consistent, whereas in allergic reactions to nickel sulphate it was generally larger and more variable in size (p less than 0.02). The two major lymphocyte subsets (T4 and T8) were randomly intermixed in both types of reaction and formed the major component of both the perivascular and diffuse dermal infiltrate, without any evidence of selective migration. The T4:T8 ratios were similar in focal and diffuse infiltrates. The number of T6 dendritic (putative Langerhans) cells in the epidermis (per mm inner epidermal length) was usually greatly reduced in irritant reactions (5-16 mm-1, mean 10 mm-1) but remained within normal limits in allergic reactions (6-33 mm-1, mean 21 mm-1) (p less than 0.001). Comparable results were seen with other irritants (mercuric chloride and benzalkonium chloride) and other allergens (neomycin sulphate, ethylene diamine and potassium dichromate). In additional experiments, pairs of biopsies were taken from the reaction and from adjacent unaffected skin. The T6 cell density in the epidermis did not significantly differ between allergic reactions and control skin. By contrast, the irritant reactions had fewer T6 cells than the control skin (p less than 0.001).     

重庆地区193例化妆品变应性接触性皮炎患者斑贴试验结果分析

 目的:分析重庆地区化妆品变应性接触性皮炎患者主要化妆品成分变应原,以便指导患者合理选择和使用化妆品,降低皮炎的发生率。方法:选取我院皮肤科门诊确诊为化妆品变应性接触性皮炎的193例患者进行化妆品成分斑贴试验,并对结果作统计学分析。结果:斑贴试验总阳性率为69.43%,合并2种及2种以上变应原的患者占50.26%,阳性率前5位的变应原分别为硫柳汞、十二烷基硫酸钠、尼泊金酯、三乙醇胺和乙二胺;女性斑贴试验阳性率为73.33%,明显高于男性,差异有统计学意义(X²=9.67,P<0.05）;青年组明显高于其他年龄组,差异有统计学意义（ X²=36.79,P<0.05）。结论：硫柳汞、十二烷基硫酸钠、尼泊金酯、三乙醇胺和乙二胺5种物质是重庆地区化妆品变应性接触性皮炎患者主要的致敏成分。化妆品变应性接触性皮炎患者以女性为主,中青年多见。     

Occupational allergic contact dermatitis and patch test results of leather workers at two Indonesian tanneries

Background. Tannery workers are at considerable risk of developing occupational contact dermatitis. Occupational skin diseases in tannery workers in newly industrialized countries have been reported, but neither the prevalence of occupational allergic contact dermatitis nor the skin‐sensitizing agents were specifically examined in those studies. Objectives. To assess the prevalence of occupational allergic contact dermatitis in Indonesian tanneries, identify the causative allergens, and propose a tannery work series of patch test allergens. Patients/methods A cross‐sectional study in all workers at two Indonesian tanneries was performed to assess the prevalence of occupational contact dermatitis via a questionnaire‐based interview and skin examination. Workers with occupational contact dermatitis were patch tested to identify the causative allergens. Results. Occupational contact dermatitis was suspected in 77 (16%) of the 472 workers. Thirteen (3%) of these 472 workers were confirmed to have occupational allergic contact dermatitis. Potassium dichromate (9.2%), N,N‐diphenylguanidine (5.3%), benzidine (3.9%) and sodium metabisulfite (2.6%) were found to be the occupationally relevant sensitizers. Conclusions. The sensitization pattern showed some differences from the data in studies reported from other newly industrial countries. We compiled a ‘tannery work series' of allergens for patch testing. A number of these allergens may also be considered for patch testing in patients with (leather) shoe dermatitis.     

Standard patch test results in patients with contact dermatitis in Israel: age and sex differences

Previous studies have shown that the prevalence of specific allergens varies by geographic area, population, age and sex. The objective of the present study was to determine the relative frequency of positive reactions to different sensitizers in Israeli patients with clinically suspected contact dermatitis (CD) and to identify possible sex and age differences. A total of 943 consecutive patients were tested for CD using the European standard patch test series. The most frequent allergen was nickel sulfate followed by potassium dichromate and fragrance mix. Positive reactions to nickel sulfate were more common among women, especially those in the younger age group (younger than 40 years). Positive reactions to balsam of Peru were more common among men, especially those in the older age group (40 years or older). This study presents the result of the standard patch test in Israel with stratification according to age and sex. The findings of the present study, combined with reports on geographic/population differences in the prevalence of specific allergens in CD, indicate the need for further investigations to identify prominent local allergens for better adaptation of the standard patch test to local needs.     

Visual scoring and laser Doppler perfusion imaging of skin irritancy induced by different nicotine patches

Background/aims: Local skin reactions are the most common reason for discontinuation of transdermal nicotine replacement therapy in smoking cessation programs. The aims of the present study were (1) to quantify the intensity of skin reactions induced by different types of nicotine patches and (2) to compare the clinical evaluation of skin erythema using visual scores with independently performed quantitative estimates of skin perfusion.
Methods: Thirty-three subjects were included in the study, each receiving 2 different types of nicotine patches (Nicotinell and Nicorette) and 1 type of placebo patch (Nicorette), placed ventrally on the upper arms according to a randomized protocol. Patches were removed after 24 h (Nicotinell) and 16 h (Nicorette), respectively, according to recommended application times. Visual scoring and laser Doppler perfusion imaging were performed 45 min after removal of patches, in a randomized order.
Results: Nicotinell patches induced the highest cumulative clinical score for skin irritancy. All 3 investigated patches gave rise to a slight but significant skin perfusion increase and individual visual scores and perfusion data correlated.
Conclusion The degree of skin irritancy and underlying perfusion increase induced by 1 daily maintenance dose of transdermal nicotine via a patch is low, but differs between patch types.     

Profile of irritant patch testing with detergents: sodium lauryl sulfate,sodium laureth sulfate and alkyl polyglucoside

The cutaneous reaction to detergents follows distinct kinetic rules: the duration of application and the irritant concentration are of major importance. The aim of this study was to evaluate the differences in kinetics of skin reaction between the standard irritant sodium lauryl sulfate (SLS), and 2 modern detergents: sodium laureth sulfate (SLES) and alkyl polyglucoside (APG). We performed patch testing with SLS and SLES (or APG) at different concentrations (0.125, 0.25, 0.5, 1.0 and 2.0%) and with different exposure times (6, 12 and 24 h). Evaluation was conducted by measurement of transepidermal water loss (TEWL) and laser Doppler flowmetry (LD) 24 h, 7 and 10 days after patch removal. We found a pronounced reaction to SLS, and a far milder one to SLES. Even at the highest concentration the skin reaction to APG was hard to detect. During the regeneration period (day 3-10) SLS showed even at day 10 an increased TEWL at all concentrations tested. The irritation due to SLES was convincingly detectable only up to day 7, whereas the APG-tested skin areas showed no significant reaction even at day 3. These results demonstrate the improvement in reduction of skin irritation achieved by development of novel detergents.     

Oral prednisone suppresses allergic but not irritant patch test reactions in individuals hypersensitive to nickel

A multicentre, randomized, double-blind, crossover study was designed to investigate the effects of prednisone on allergic and irritant patch test reactions. 24 subjects with known allergy to nickel were recruited and patch tested with a nickel sulfate dilution series in aqueous solution, 5% nickel sulfate in petrolatum and 2 dilution series of the irritants nonanoic acid and sodium lauryl sulfate. The subjects were tested x2, both during treatment with prednisone 20 mg oral daily and during placebo treatment. The total number of positive nickel patch test reactions decreased significantly in patients during prednisone treatment. The threshold concentration to elicit a patch test reaction increased and the overall degree of reactivity to nickel sulfate shifted towards weaker reactions. The effect of prednisone treatment on the response to irritants was divergent with both increased and decreased numbers of reactions, although there were no statistically significant differences compared with placebo. It is concluded that oral treatment with prednisone suppresses patch test reactivity to nickel, but not to the irritants tested.     

Patients with vulval pruritus: patch test results

Background:  Persistent vulval pruritus is a frequent problem and patients may not show signs of a primary vulval dermatosis. Allergic contact sensitivity is an important factor in such patients but may also occur as a secondary event in women with vulval dermatoses.
Objectives:  We aim to describe women with vulval pruritus who were evaluated for vulval dermatoses. We patch tested to help define or exclude allergens.
Methods:  In a 3-year period, 50 women with vulval pruritus were examined for existence of vulval dermatosis. All the patients were patch tested to the European Baseline Series, medicaments, preservatives, vehicles, cosmetics and products they routinely used.
Results:  Ages of the patients ranged from 22 to 62 years (mean 39.9 ± 9 years) and duration of the diseases ranged from 0.5–360 months (mean 56.1 ± 65.6 months). 52% of the women had at least 1 positive patch test. 8 patients (16%) had 1 or more relevant allergic positive reactions. The relevant allergens were usually cosmetics, preservatives and medicaments.
Conclusions:  Women with vulval pruritus were patch tested to help define or rule our allergens. Contact allergy incidence in these patients is high. The relevant allergens were usually cosmetics, preservatives and medicaments.