Contact dermatitis in Alstroemeria workers.
Hand dermatitis is common in workers in the horticultural industry. This study determined the prevalence of hand dermatitis in workers of Alstroemeria cultivation, investigated how many workers had been sensitized by tulipalin A (the allergen in Alstroemeria) and took stock of a wide range of determinants of hand dermatitis. The 12-month period prevalence of major hand dermatitis amounted to 29.5% whereas 7.4% had minor dermatitis. Of these workers, 52.1% were sensitized for tulipalin A. Several personal and work-related determinants played a role in the multifactorial aetiology of hand dermatitis. Factors which showed a significant relationship with major hand dermatitis were: female sex, atopic dermatitis, chapped hands and the frequency of washing hands. It may be concluded that the Alstroemeria workers are a population at risk of developing contact dermatitis and it might be useful to carry out an educational campaign to lower the high prevalence. (+info)
Sputum eosinophils and exhaled nitric oxide during late asthmatic reaction in patients with western red cedar asthma.
Examination of sputum for eosinophils and measurement of exhaled nitric oxide have been proposed as noninvasive methods of assessing airway inflammation in asthma. The use of these tests in the evaluation of patients with occupational asthma has not been reported. This study investigated the changes in sputum eosinophils and exhaled NO before and at intervals after inhalation challenge with plicatic acid in patients with suspected western red cedar asthma. Of 17 subjects who underwent challenge, nine had a positive bronchoconstrictor reaction (responders) and eight had a negative reaction (nonresponders). At 6 and 24 h after plicatic acid challenge, there was a significant increase in sputum eosinophils among responders, which was inversely related to the fall in forced expiratory volume in one second (FEV1) at 6 h. An increase in sputum eosinophils was also found in three nonresponders. Levels of exhaled NO increased at 24 h after challenge with plicatic acid in both responders and nonresponders, being significant only in nonresponders. No correlation was found between the increase in nitric oxide and the magnitude of the functional changes in the airways. There were significant correlations between the degree of sputum eosinophilia and the level of exhaled NO before and after methacholine and plicatic acid challenge. In conclusion, the late asthmatic reaction induced by plicatic acid in patients with western red cedar asthma is associated with an increase in sputum eosinophils. The usefulness of measuring sputum eosinophils and exhaled nitric oxide in the clinical evaluation of patients with suspected occupational asthma caused by low molecular weight compounds has yet to be determined. (+info)
Sensitivity and exposure to indoor allergens in adults with differing asthma severity.
In asthma, it is uncertain whether there is an association between degrees of exposure to domestic allergens and asthma severity. The pattern of sensitivity and exposure to common indoor allergens was examined in subjects with differing asthma severity. Sensitivity to house dust mite, dog and cat allergen and exposure to Der p 1, Can f 1 and Fel d 1 were assessed by skin prick tests and settled dust analysis in 28 subjects with severe asthma and 28 age- and sex-matched subjects with mild asthma (two declined skin prick test). All severe asthmatic subjects had at least one positive skin test and 20 of the 28 subjects were positive to all three allergens. Fourteen of the 26 subjects with mild asthma who took skin prick tests were positive to at least one, and one of these subjects was positive to the three allergens tested. Except for bedroom Fel d 1, the proportion of severe asthmatics both sensitized and exposed to each allergen at each site was significantly greater than the proportion sensitized and exposed in the mild asthma group. The geometric mean allergen concentrations, with the exception of bedroom Fel d 1, were greater in sensitized severe asthmatics than the sensitized mild asthmatics, which was significant for Der p 1 in bedroom samples and Can f 1 in bedroom and living room samples. These results support an association between the degrees of domestic allergen exposure in sensitized individuals and asthma severity. (+info)
A quantitative comparison of induction and challenge concentrations inducing a 50% positive response in three skin sensitization tests; the guinea pig maximization test, adjuvant and patch test and Buehler test.
The sensitivities of three skin sensitization tests such as the Guinea pig maximization test (GPMT), Adjuvant and patch test (APT) and Buehler test (BT), were quantitatively compared with reference to induction and challenge concentrations. Four chemical which had different physico-chemical properties (octanol-water partition coefficient (logP) and reactivity with NH2-group) were used in order to clarify the effect of the physico-chemical properties of chemicals on the sensitivity of the different methods. The induction concentrations inducing a 50% positive response (IC50) demonstrated extreme variation with the three methods. For example, the BT/GPMT ratio of IC50 values for 2,4-dinitrochlorobenzene was 33, whereas that for maleic anhydride was 300,000. The results were thought to be caused by difference properties such as the logP and reactivity of chemicals. This correlation was confirmed by using 2-dodecen-1-yl succinic anhydride, which had the same reactivity but higher logP than that of maleic anhydride. On the other hand, the challenge concentrations inducing 50% positive responses (CC50) were less affected by the methods and the BT/GPMT ratios for CC50 values were all within a 10-fold range. These results suggest that the sensitivity might be strongly different with reference to induction concentration, but not challenge concentration among the three methods. (+info)
Nickel-induced proliferation of both memory and naive T cells in patch test-negative individuals.
Lymphocyte transformation test has often been used as an in vitro test for nickel allergy. We have previously demonstrated the presence of nickel-reactive T cells in individuals with no history of allergic disease and with a negative patch test towards NiSO4. In this study, we show that this proliferative response was mainly confined to T cells within the CD4+ subset. In contrast to conventional recall antigens such as tetanus toxoid, in vitro stimulation using NiSO4 activated both FACS-purified CD4+CD45RA+ 'naive' and CD4+CD45RO+ 'memory' T cells. To determine which cell population reacted with nickel to induce T cell activation, peripheral blood mononuclear cells were separated into macrophages and non-adherent, HLA-DR-depleted T cells. We found that preincubation of monocytes/macrophages but not T cells with NiSO4 resulted in subsequent T cell proliferation. This result demonstrated that nickel did not exhibit any direct effect on the T cell. Furthermore, the NiSO4-induced T cell proliferation could be blocked by antibodies towards MHC class II (HLA-DR) molecules. Our results substantiate the concept that individuals with a negative patch test towards NiSO4 contain in their peripheral blood T cells capable of recognizing nickel or nickel-modified peptides. In contrast to conventional recall antigens, both memory and naive T cells were activated. Thus, when compared with data obtained from nickel-allergic individuals, this study shows a comparable nickel-inducible T cell activation in non-allergic individuals. (+info)
Occupational induction of hypersensitivity after an accidental exposure to chloromethylisothiazolinone and methylisothiazolinone (CMI/MI) in an industrial worker.
A process worker in a paper chemical plant developed an immediate local dermal irritation and delayed bullous dermatitis due to induction of hypersensitivity following an accidental exposure to chloromethylisothiazolinone and methylisothiazolinone (CMI/MI) biocide. Contact allergy to the isothiazolinone mixture was confirmed by skin patch testing. The dermatitis healed in four weeks, and the worker was advised to avoid all CMI/MI containing products. In a one-year follow-up he did not present with any further skin symptoms. Preventive measures are important for avoiding induction of hypersensitivity to concentrated CMI/MI solutions in industrial workers. (+info)
Analysis of aldehyde dehydrogenase 2 gene polymorphism and ethanol patch test as a screening method for alcohol sensitivity.
To assess clinical availability of the aldehyde dehydrogenase (ALDH) 2 gene polymorphism to detect alcohol sensitivity among a Japanese population, we determined the ALDH 2 genotypes and also compared to an ethanol patch test in 119 young Japanese. Their alcohol sensitivity was evaluated by a questionnaire on the frequency of alcohol-associated symptoms when they drink. Genomic DNA was extracted from blood samples and amplified by polymerase chain reaction (PCR). PCR primers were flanking the polymorphic region in exon 12 of the ALDH 2 gene. The distribution of the typical homozygote, the heterozygote and the atypical homozygote was 63.9, 31.9 and 4.2%, respectively. Gene frequencies of the typical and atypical alleles calculated from the genotype frequencies were 0.80 and 0.20. The atypical genotypic homozygotes were positively associated with facial flushing symptom, but not with positive response for ethanol patch test. These results indicate that ALDH 2 genotypes determination is essential to detect alcohol sensitivity whereas the ethanol patch test has some limitations. (+info)
The CXCR3 activating chemokines IP-10, Mig, and IP-9 are expressed in allergic but not in irritant patch test reactions.
Differentiation between allergic and irritant contact dermatitis reactions is difficult, as both inflammatory diseases are clinically, histologically, and immunohistologically very similar. Previous studies in mice revealed that the chemokine IP-10 is exclusively expressed in allergic contact dermatitis reactions. In the present study, we investigated whether the mRNA expression of IP-10 and the related CXCR3 activating chemokines, Mig and IP-9 are also differentially expressed in human allergic contact dermatitis and irritant contact dermatitis reactions. Skin biopsies from allergic (13 cases) and sodium lauryl sulfate-induced irritant patch test reactions (13 cases), obtained 1-72 h after patch testing, were studied by means of an in situ hybridization technique. Results of chemokine mRNA expression were correlated with clinical scoring, histology, and immunohistochemical data including the proportion of inflammatory cells expressing CXCR3, the receptor for IP-10, Mig, and IP-9, and ICAM-1 and HLA-DR expression on keratinocytes. IP-10, Mig, and IP-9 mRNA were detected in seven of nine allergic contact dermatitis reactions after 24-72 h, but not in sodium lauryl sulfate-induced irritant contact dermatitis reactions. ICAM-1 expression by keratinocytes was only found in allergic contact dermatitis reactions and correlated with chemokine expression. Moreover, up to 50% of the infiltrating cells in allergic contact dermatitis expressed CXCR3, in contrast to only 20% in irritant contact dermatitis reactions. In conclusion, we have demonstrated differences in chemokine expression between allergic contact dermatitis and irritant contact dermatitis reactions, which might reflect different regulatory mechanisms operating in these diseases and may be an important clue for differentiation between allergic contact dermatitis and irritant contact dermatitis reactions. (+info)