Nickel(II) sulphate-induced allergic contact dermatitis as experimental tool to investigate inflammatory pruritus in humans.

BACKGROUND AND OBJECTIVESContact allergy is associated with a significant morbidity all over the world. This study was performed to investigate the pattern of sensitization by contact allergens in the local population.DESIGN AND SETTINGRetrospective study to investigate patch test reactivity among patients with clinical diagnosis of contact dermatitis who were referred to the allergy clinic at the King Khalid University Hospital, Riyadh, between April 2008 and March 2010.PATIENTS AND METHODSOf the 196 patients referred to the allergy clinic over the 2-year period, 91 (46.4%) patients reacted to one or more patch test allergens, and these patients were included in this study. The study group included 82 (91.1%) of Saudi nationality and 9 (8.9%) patients of other nationalities. The patch test was performed using the T.R.U.E TEST, containing 24 allergens/allergen mixes.RESULTSOf the 91 cases who reacted positively to one or more allergens, 67 (73.6%) were females with a mean age of 37 (8.3 years) and 24 (26.4%) were males with a mean age of 34 (11.6 years). Thirty-three (36.2%) patients reacted to nickel sulfate, 14 (15.3%) to p-phenylenediamine, 13 (14.2%) to p-tert-butylphenol-formaldehyde resin, 13 (14.2%) to thimerosal, and 9 (9.8%) to colophony. Reactivity against the rest of the allergens was not remarkable. A significantly higher percentage of females reacted to nickel sulfate (84.8% vs 15.2% in males; P=.0001), p-tert-butylphenol-formaldehyde resin (92.3% vs 7.7%; P=.0001), and thimerosal (76.9% vs 23.1%; P=.03).CONCLUSIONSPatch test reactivity to nickel sulfate was high. The pattern of contact allergy observed in this study indicates the need for large-scale investigations to identify local allergens responsible for contact allergy and for formulation of policies directed towards avoidance of exposure.

Allergic contact dermatitis and irritant contact dermatitis have different pathogenic mechanisms. It is therefore plausible that the epidermal expression of HLA-DR and the invariant chain associated with antigen processing and presentation might differ between allergic contact dermatitis and irritant contact dermatitis. We have quantified the volume of epidermal HLA-DR and invariant chain reactivity and the total epidermal volume in allergic contact dermatitis and irritant contact dermatitis using confocal laser scanning microscopy and indirect immunofluorescence on acetone-fixed 25 microns thick vertical skin sections. Eight nickel allergic patients were patch-tested with 5% nickel sulfate and 8 healthy volunteers were patch-tested with 4% sodium lauryl sulfate. Skin biopsy specimens were taken at 0, 6, 24, and 72 h after application of the patch tests. Sodium lauryl sulfate induced a statistically significant increased epidermal volume at 24 h and 72 h compared to 0 h and 6 h (p < 0.003 and p < 0.001, respectively), whereas an increase in epidermal volume in the allergic contact dermatitis group was not noted until 72 h after patch testing with nickel sulfate compared to 0, 6 h (p < 0.001) and 24 h (p < 0.004). No significant changes in the epidermal volume of HLA-DR reactivity were found at any time point within or between the two groups, nor was there any significant change in the epidermal volume of invariant chain reactivity in the allergic contact dermatitis group. In the irritant contact dermatitis group, however, the epidermal volume of invariant chain reactivity was significantly reduced from 17 +/- 8 x 10(3) microns 3 at 24 h to 9 +/- 3 x 10(3) microns 3 at 72 h (p < 0.04), which was also significantly lower than the 14 +/- 4 x 10(3) microns 3 observed in allergic contact dermatitis at 72 h (p < 0.01). Furthermore, the invariant chain expression was significantly lower than the HLA-DR reactivity in the irritant contact dermatitis group at 72 h (p < 0.001). The decrease of invariant chain reactivity at 72 h in irritant contact dermatitis might reflect an epitope-induced alteration by sodium lauryl sulfate or a down-regulated biosynthesis of the invariant chain due to variance in local cytokine production between allergic contact dermatitis and irritant contact dermatitis.

Allergic skin diseases

Occupational allergic contact dermatitis is more prevalent than irritant contact dermatitis: A 5-year study

Healthcare workers (HCWs) are at risk of developing occupational skin disease (OSD). To ascertain the causes of OSD in Australian HCWs in a tertiary referral clinic. A retrospective review was performed of patients assessed at the Occupational Dermatology Clinic in Melbourne from 1993 to 2014. Of 685 HCWs assessed in the clinic over a period of 22 years, 555 (81.0%) were diagnosed with OSD. The most common diagnosis was irritant contact dermatitis (ICD) (79.1%), followed by allergic contact dermatitis (ACD) (49.7%). Natural rubber latex allergy was also relatively frequent (13.0%). The major substances causing ACD were rubber glove chemicals (thiuram mix and tetraethylthiuram disulfide), preservatives (formaldehyde, formaldehyde releasers, and isothiazolinones), excipients in hand cleansers, which are hard-to-avoid weak allergens, and antiseptics. ACD caused by commercial hand cleansers occurred more frequently than ACD caused by alcohol-based hand rubs (ABHRs). Occupational ICD was mostly caused by water/wet work and hand cleansers, and environmental irritants such as heat and sweating. Understanding the causes of OSD in HCWs is important in order to develop strategies for prevention. We suggest that skin care advice should be incorporated into hand hygiene education. The use of ABHRs should be encouraged, weak allergens in skin cleansers should be substituted, and accelerator-free gloves should be recommended for HCWs with OSD.

Epidemiological survey of contact dermatitis in Italy (1984–1993) by GIRDCA (Gruppo Italiano Ricerca Dermatiti da Contatto e Ambientali)

Epidemiological Survey of Contact Dermatitis in Italy (1984-1993) by GIRDCA (Gruppo Italiano Ricerca Dermatiti da Contatto e Ambientali)

Skin diseases are among the most common occupational diseases, but detailed analyses on their epidemiology, diagnoses, and causes are relatively scarce. To analyze data on skin disease in the Finnish Register of Occupational Diseases (FROD) for (1) different diagnoses and (2) main causes of allergic contact dermatitis (ACD). We retrieved data on recognized cases with occupational skin disease (OSD) in the FROD from a 12-year-period 2005-2016 and used national official labor force data of the year 2012. We analyzed a total of 5265 cases, of which 42% had irritant contact dermatitis (ICD), 35% ACD, 11% contact urticaria/protein contact dermatitis (CU/PCD), and 9% skin infections. The incidence rate of OSD in the total labor force was 18.8 cases/100 000 person years. Skin infections concerned mainly scabies in health care personnel. Twenty-nine per cent of the ACD cases were caused by plastics/resins-related allergens, mainly epoxy chemicals. Other important causes for ACD were rubber, preservatives, metals, acrylates, and hairdressing chemicals. Cases of occupational ACD due to isothiazolinones reached a peak in 2014. Our analysis confirms that epoxy products are gaining importance as causes of OSD and the isothiazolinone contact allergy epidemic has started to wane.

Allergic Contact Dermatitis and Patch Testing in Skin of Color Patients.

Nickel allergy in the United States: A public health issue in need of a “nickel directive”

Protection from Occupational Allergens

Contact dermatitis is an inflammatory skin disease induced by direct contact of a external agent to the skin. It can be classified into two main types: Irritant contact dermatitis and Allergic contact dermatitis. Irritant contact dermatitis represents a non-specific cutaneous response to the toxic or physical effects of environmental agents, while Allergic contact dermatitis represents a specific type IV hypersensitivity reaction to specific haptens. Both types are characterized by a highly variable clinical presentation that includes erythema, papules, vesicles, bullae, scaling and erosions in acute cases, and papules, plaques, lichenification, hyperkeratosis and fisures in the chronic. Pruritus is a very common symptom most frequently associated with Allergic contact dermatitis but also frequent in Irritant contact dermatitis. Furthermore, occasionally pruritus may be the leading or only symptom that guides the clinician to suspect the diagnosis of Contact dermatitis, as it is in the case of Allergic contact dermatitis of the anogenital region or when the process occurs in the elderly. Although the mechanisms underlying the pathogenicity of the inflammatory cutaneous response in irritant and allergic contact dermatitis has been widely studied, little is known about the mechanisms leading to pruritus. This chapter summarizes the most important aspects of contact dermatitis in these specific situations as well as the last insights into the pathogenicity of pruritus in contact dermatitis.

Irritant contact dermatitis (ICD), provoked by work materials or workflows, is believed to be a frequent cause of occupational skin disease (OSD). Data of incidence rates of ICD within different occupations are inadequate. We conducted a population-based study to identify occupational groups at risk for irritant and allergic contact dermatitis (ACD). The data are based on all workers' compensation claims reported to our register of OSDs in Northern Bavaria [Berufskrankheitenregister Haut-Nordbayern (BKH-N)], Germany. From 1990 to 1999, 5285 patients had their cases completely assessed and recorded by government-employed physicians. We calculated the incidence rates of ICD and ACD in various occupations, divided into 24 occupational groups, in co-operation with the German State Institute of Labor and Occupation; there were a known total number of employees in each of the occupations. In these groups 3097 (59%) patients with OSD were observed, with an overall annual incidence rate of 4.5 patients per 10,000 workers for ICD, compared with 4.1 patients per 10,000 workers for ACD. The highest ICD annual incidence rates were found in hairdressers (46.9 per 10,000 workers per year), bakers (23.5 per 10,000 workers per year), and pastry cooks (16.9 per 10,000 workers per year); at the same time ICD was the main diagnosis of OSD in pastry cooks (76%), cooks (69%), food processing industry workers and butchers (63%), mechanics (60%), and locksmiths and automobile mechanics (59%). The results of a questionnaire showed frequent skin contact with detergents (52%), disinfectants (24%), and acidic and alkaline chemicals (24%) in the workplace. Based on the incidence data of the BKH-N, this study identified occupational groups with a high risk of ICD. Different frequencies of ICD and ACD within a single group are demonstrated. The frequent usage of detergents is being addressed because of the introduction of German legislation of recent date (the Approved Code of Practice 531 on 'wet work').

Background: Occupational contact dermatitis, especially in hand, is one of the most common occupational disorders. The present study aimed at evaluating patients with occupational allergic contact dermatitis (ACD) caused by common allergens based on occupation type and disease history.Methods: This cross-sectional study aimed at evaluating the data of the patients with probable diagnosis of ACD in Center for Research and Training in Skin Diseases and Leprosy (CRTSDL) in Iran. In the present study, 946 patients were assessed from different regions of Iran. One hundred fifty-one cases with positive patch test and relevant exposure were entered into the study; data related to their occupation and disease activity history were evaluated and recorded. Then, factors related to disease activity history were assessed considering the occupational groups and common exposures.Results: Nickel sulphate was the most common allergen in the 151 patients. Disease activity was constant in 29.8% of the patients; it increased in 27.8%, and decreased just before doing the patch test in 42.4%. Of the patients, 52.3% were getting worse during the working days. Occupational groups were significantly different in age and gender. Disease duration was also different in the occupational groups (p=0.001). The least disease duration was observed in healthcare workers, and the most in service workers. Lesions in the foot were related to period of employment. In administrative work group, (teachers, technicians and housewives) disease activity was decreased in the most cases, while it was increased in most patients of service workers (p=0.086).Conclusion: The present study, similar to previous reports, revealed that nickel sulphate is the most common allergen in ACD cases. Moreover, it was found that the symptoms of disease activity remained constant or increased in a significant proportion of the cases during the working days. Therefore, these workers should seriously follow up on this matter and change their occupation, or limit the exposure to allergens.

ObjectiveIrritant contact dermatitis and Allergic contact dermatitis are two distinct forms of contact dermatitis. Allergic contact dermatitis is a Type 4 (delayed-type) hypersensitivity reaction that occurs during subsequent contact with an allergen to a previously sensitized person. The number of allergens that cause allergic contact dermatitis is increasing day by day. Although it is not the gold standard for the detection of these allergens, skin patch testing is a very helpful method. This study aimed to determine the most common contact allergens in the pediatric age group.Material and MethodsAll patients with the diagnosis of contact dermatitis who underwent a skin patch test (TRUE TEST) in the department of Pediatric Allergy and Immunology between March 2017–February 2018 were enrolled in this study. The patch test was evaluated 72 hours later by the same physician and interpreted as recommended by the American Academy of Dermatology. In addition to the patient files, demographic and clinical characteristics, localization of lesions, and itch score according to visual analog scale were recorded.ResultsA total of 80 children enrolled in the study; 45 (56.3%) were girls and 35 (43.7%) were boys. The mean age of the children was 7.37±3.84 years and 57.5% of the patients who underwent skin patch testing had a positive response to at least one or more allergens. The most common allergens were Nickel sulfate, CI + Me-Isothiazolinone, Thiuram Mix, Formaldehyde, and P-tert-butylphenol formaldehyde resin (14.8%, 10%, 6.3%). There was no difference in terms of age, sex, duration of complaints, and pruritus score according to nickel sensitization.ConclusionIn the presence of chronic dermatitis in children, allergic contact dermatitis should be considered in the differential diagnosis. The culprit allergen should be determined. Also, the most common contact allergen is Nickel Sulphate in the world and the increased sensitization to other allergens is due to the increased contact of children with cosmetics and different contact allergens.