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Biomedical subjects

J R Nethercott

Publications and source records attributed to J R Nethercott.

At least 19 recordsLinked to original sources
PubMed1999

An environmental hazard assessment of low-level dermal exposure to hexavalent chromium in solution among chromium-sensitized volunteers.

To evaluate the potential for elicitation of allergic contact dermatitis from contact with standing water in the environment, 26 persons known to be allergic to hexavalent chromium [Cr(VI)] were exposed to 25 to 29 mg/L Cr(VI) by immersion of one arm for 30 minutes per day on 3 consecutive days in a potassium dichromate bath. Sixteen of the 26 volunteers demonstrated either no or an equivocal response to the Cr(VI) challenge. Ten of the volunteers developed a few papules or vesicles (1 to approximately 15), mild redness, and pruritus on the Cr(VI)-challenged arm. Histopathological examination of the papules revealed spongiosis and perieccrine and perivascular inflammation. The responses were diagnosed as acute perieccrine reactions. It was concluded that exposure to similar concentrations of Cr(VI) in the environment does not pose an allergic contact dermatitis hazard, even to Cr-sensitized persons.

Biopsy↗
PubMed1998

North American Contact Dermatitis Group patch test results for the detection of delayed-type hypersensitivity to topical allergens.

BACKGROUND: Allergic contact dermatitis is a significant cause of cutaneous disease affecting many individuals. Patch testing, when used properly, often provides support for the diagnosis of allergic contact dermatitis. OBJECTIVE: This article reports patch testing results from July 1, 1994, to June 30, 1996, by the North American Contact Dermatitis Group (NACDG). METHODS: Patients evaluated in our patch test clinics were tested with the same screening series of allergens by the use of a standardized patch testing technique. The data from these patients were recorded on a standard computer entry form and analyzed. RESULTS: Forty-nine allergens were tested on 3120 patients. Budesonide was added to the series in July 1995 and tested on 1678 patients. Of these patients, 66.5% had positive allergic patch test reactions, and 57% had at least one allergic reaction that was felt to be clinically relevant to the present or past dermatitis. The 20 screening allergens commercially available to United States dermatologists in the Allergen Patch Test Kit, accounted for only 54.1% of the patients with positive allergic reactions. The additional 30 allergens on the NACDG screening series accounted for 47% of patients with positive allergic reactions. Had the Allergen Patch Test Kit alone been used, 12.4% of all patients tested may have had their disease misclassified as a nonallergic disorder, and an additional 34.4% of all tested patients would not have had their allergies fully defined. Among those patients with positive responses to the supplemental allergens, 81% of the responses were of present or past relevance. The 12 most frequent contact allergens were nickel sulfate, fragrance mix, thimerosal, quaternium-15, neomycin sulfate, formaldehyde, bacitracin, thiuram mix, balsam of Peru, cobalt chloride, para-phenylenediamine, and carba mix. The present relevance varied with the specific allergen from 10.7% (thimerosal) to 85.7% (quaternium-15). Among newer allergens, methyldibromoglutaronitrile/phenoxyethanol (cosmetic preservative) caused positive allergic reactions in 2% of the patients; tixocortol-21-pivalate and budesonide (corticosteroids), in 2.0% and 1.1% of the patients, respectively; and ethylene urea/melamine formaldehyde mix (textile resin), in 5% of the patients. CONCLUSION: The usefulness of patch testing is enhanced with the number of allergens tested, because allergens not found on the commercially available screening series in the United States frequently give relevant allergic reactions.

Allergens↗
PubMed1997

Results of patch testing with a special series of rubber allergens.

The purpose of this study was to examine the results of patch testing with the rubber components on a standard screening tray and compare them with the results of testing with a special series of 27 rubber components (rubber tray). 1670 patients were patch tested with the screening tray and 317 of these were also tested with the rubber tray. 16% of those tested with the rubber tray had a positive response to at least 1 of the rubber allergens on the screening tray and 22% had a positive response to at least 1 of the allergens on the rubber tray. The most common positive response to the rubber tray allergens was to tetramethylthiuram monosulfide. There were no responses to 3 of the components on the rubber tray and there was only 1 positive response to a further 4 components. The diagnostic test characteristics of the rubber components on the screening tray were examined using the rubber tray as the gold standard. The sensitivity of the screening tray was 94%, specificity 51%, positive predictive value 87% and negative predictive value 71%. Of the 317 tested, 11% were found to have a positive to a substance on the rubber tray that was not evident from the results of the screening tray.

Adult↗
PubMed1997

The Americans With Disabilities Act and dermatologists.

The passage and implementation of the Americans With Disabilities Act of 1990 (ADA) has established certain rights in law for persons with disabilities, including patients with skin disease. For workers in workplaces employing more than 15 workers, management may not exclude a worker from a job unless it can be objectively demonstrated that their skin disease will make it impossible for them to perform the essential functions of the job. Employers, at their expense, are now required to provide those disabled with skin disease with reasonable accommodation to allow them to perform their jobs while having their skin impairment. Unless the skin impairment can be shown to place the worker or their fellow workers at material risk to their health, the employer may not exclude them from working--even if the employer is concerned that it may make their skin disease worse. The act applies both to new employees and those acquiring disabling skin disease who are employed and wish to stay at work or return to work. Arbitration of dispute between employees and management are the responsibility of the Equal Employment Opportunities Commission (EEOC), a federal agency responsible for the legislation.

Dermatology↗
PubMed1996

Aeroallergen patch testing for patients presenting to contact dermatitis clinics.

BACKGROUND: The role of aeroallergens in the production of allergic contact dermatitis or "allergic contact dermatitis-like" atopic dermatitis is controversial. Although techniques and allergens lack standardization, most studies find positive patch test results in 30% to 40% of patients with atopic dermatitis. OBJECTIVE: Our purpose was to determine the prevalence and clinical significance of positive aeroallergen patch tests in patients undergoing standard patch testing for suspected "nonaeroallerge" allergic contact dermatitis. METHODS: One hundred three consecutive patients referred to three university patch test clinics for patch testing were alos patch tested with six common aeroallergens in glycerine-dust, mold, cat epithelium, tree, grass, and weed-as well as with a glycerine control. Patches were removed at 48 hours. Readings were performed at this time and at 3 to 7 days after initial application. RESULTS: As determined by history, these 103 patients included 16 patients with both atopic dermatitis and mucosal atopy, 10 patients with atopic dermatitis only, 22 patients with mucosal atopy only, and 55 patients with neither atopic dermatitis nor mucosal atopy. Allergic reactions were seen to one aeroallergen in five patients (three with atopic dermatitis and mucosal allergy, and two with no history of atopy). The prevalence (3 of 16 [18.8%]) of reactions in patients with both atopic dermatitis and mucosal allergy was significantly greater than the prevalence (2 of 87 [2.3%]) in patients with only one or neither of these two atopic disorders (p = 0.02). None of these aeroallergen contact hypersensitivities were deemed significant in the patients' current dermatitis. However, reactions were of past relevance in two of the three patients with atopic dermatitis and mucosal allergy. CONCLUSION: In this referral group, none of the six common aeroallergens tested was relevant in the origin of suspected "nonaeroallergen" allergic contact dermatitis. This study suggests that aeroallergen patch testing is of little use in the evaluation of patients referred for routine patch testing for suspected "nonaeroallergen" allergic contact dermatitis. Similar but larger studies inclusive of the assessment of relevance, as well as masked controlled clinical trials assessing the effect of aeroallergen exposure and avoidance, are needed to evaluate this issue more fully.

Adult↗
PubMed1995

Results of ophthalmic examinations of 29 alpacas.

Analysis of the results of ophthalmic examinations of 29 alpacas (Lama pacos) revealed a direct relationship among coat color, iris color, and ocular fundus pigmentation. Alpacas with light-pigmented coats had iris color that included combinations of gray, blue, and brown, and had reduced pigmentation of the ocular fundi. Alpacas with dark coats had brown irides and pigmented ocular fundi. Eleven alpacas had evidence of ophthalmic conditions, including bilateral conjunctivitis (1); formation of a superficial corneal scar (1); formation of posterior synechiae and anterior cataracts (4); development of a deep corneal scar with anterior synechiae, buphthalmia, a subluxated lens, and cataracts (1); development of focal incipient primary cataracts (2); formation of vitreous opacities (1); and development of a unilateral optic nerve coloboma (1).

Animals↗
PubMed1995

Work outcome in workers with occupational skin disease.

We carried out a follow-up study of employment outcome for 230 workers with a diagnosis of occupational skin disease who were at least 2 years postdiagnosis. Seventy-eight percent of the workers were working, but 57% of those working had changed jobs, 67% because of their skin problem. Thirty-one percent had lost no time from work because of their skin disease, while 35% had lost at least 1 month. Forty-three percent had applied for workers' compensation benefits, and 87% of those who had applied were successful in their claims. Older workers were more likely to be unemployed and to have applied for workers' compensation benefits. Women were less likely to have lost time from work and to have applied for workers' compensation. Those who had changed their jobs tended to have a better outcome with respect to active dermatitis, though they had lost more time from work and had more often applied for workers' compensation benefits.

Absenteeism↗
PubMed1995

Exposure characteristics and cutaneous problems in operating room staff.

Health care personnel have exposure to a variety of cutaneous irritants and allergens and a high prevalence of cutaneous problems. The objectives of this exploratory study were to characterize the exposures and determine the prevalence of cutaneous symptoms and findings in operating room personnel, and to examine relationships between exposure characteristics and cutaneous outcomes. A questionnaire and standardized hand examination were used to assess the exposures and cutaneous status of operating room personnel. 184 operating room staff (90% of the eligible population) were assessed. Current skin problems were reported by 26%. Hand examination revealed that 9% had findings consistent with eczema and 10% changes of moderate dryness. A variety of preventive practices were being used by those with symptoms or findings. Cutaneous problems are common in operating room personnel. The use of preventive strategies (changing the type of gloves worn or the type of soap used for scrubbing, the use of glove liners and emollients) varied between different groups. These workers might benefit from more education regarding cutaneous hazards, preventive stategies and the importance of appropriate investigation of these problems.

Adult↗
PubMed1995

Concomitant positive patch test results with standard screening tray in North America 1985-1989.

Responses to patch test substances may occur contemporaneously. Such simultaneous reactions may reflect concomitant sensitization to 2 dissimilar allergens to which concurrent exposure has taken place (e.g., ethylenediamine dihydrochloride and neomycin). It may occur when the individual has been exposed to only 1 of the substances and exhibits a response to other substances of similar chemical structure (i.e., cross-sensitization such as between para-phenylenediamine and benzocaine). Such simultaneous responses may also be chance occurrences, reflecting multiple sensitization or the result of altered response due to the "angry back syndrome". This investigation established that such concurrence of response is not uncommon and adds further documentation to the literature of these associations in patch test responses.

Adult↗
PubMed1994

Disease outcome in workers with occupational skin disease.

BACKGROUND: Occupational contact dermatitis (OCD) contributes significantly to the burden of occupational disease, but there is little known about prognostic factors. OBJECTIVE: The study was designed to determine the health status of workers with OCD at least 2 years after diagnosis and to identify risk factors related to prognosis. METHODS: A questionnaire study was conducted of workers with a diagnosis of work-related skin disease. RESULTS: Of the 201 workers with OCD, 76% noted improvement and 40% reported that they were currently free of any eruption. Approximately one third noted that their skin disease interfered with household, work, or recreational activities. The key prognostic factor appeared to be sex because women reported a better outcome. Diagnosis and atopic status tended to be related to some outcomes, whereas age was not. CONCLUSION: Examination of other possible factors, some of which may be associated with sex, that might affect outcome should be undertaken to gain a better understanding of possible management strategies. A retrospective study has methodologic limitations and a prospective intervention trial should yield more information.

Adult↗
PubMed1994

Safe concentrations for dermal allergens in the environment.

Recent work studies have examined the relationship between allergen dose per unit of skin surface exposed and the elicitation of response for chromium. The use of such data to arrive at levels in environmental contactants is discussed with reference to soil contaminated with chromium.

Chromium↗
PubMed1993

The performance of specialized collections of bisphenol A epoxy resin system components in the evaluation of workers in an occupational health clinic population.

Epoxy resin of the bisphenol A type (ERBA) is a common cause of occupational contact dermatitis. 167 patients with a history of potential exposure were patch tested with epoxy resin (molecular weight 340) (ERBAM) 1% in pet. and with a number of other ingredients in ERBA systems. 18% of the test patients exhibited a positive response to ERBAM. Phenyl glycidyl ether was the most frequent system component other than ERBAM itself to elicit a positive response (6.1%). Approximately 80% of those tested were unresponsive to ERBAM or any other of the system components, while 20% exhibited a positive response to one or more of the test materials. Only a small % were positive to system materials, but negative to ERBAM, in keeping with previous studies. The study suggests that there is a marginal benefit to testing with other than ERBAM 1%, except in instances where there is known exposure to another ERBA system ingredient, in which event, the patient should also be tested with the specific material to which they have been exposed if there is no response to ERBAM.

Benzhydryl Compounds↗
PubMed1992

Scabies in chronic health care institutions.

BACKGROUND: The diagnosis and management of outbreaks of scabies in health care facilities may be difficult. As there is little information available regarding the extent of this problem we conducted a questionnaire study to provide an indication of the occurrence of scabies in chronic health care facilities in the province of Ontario, Canada. It also documented the facilities' approach to the management of the disease. OBSERVATIONS: Two outbreaks of scabies in chronic health care facilities are described. The questionnaire study revealed that 25% of the institutions reported that they had problems with scabies over a 1-year period. A minority had a written policy with respect to dealing with the management of scabies, particularly in the setting of a mass outbreak. CONCLUSIONS: Scabies is a common problem in chronic health care facilities; however, diagnosis and management may be difficult. The development of a specific protocol for the management of such outbreaks by the appropriate public health agencies would be useful.

Adult↗
PubMed1991

Is a worker's understanding of their diagnosis an important determinant of outcome in occupational contact dermatitis?

The possible effect of an individual's knowledge of their diagnosis on their disease outcome was examined in a group of 230 workers with occupational contact dermatitis. The workers were surveyed with an interviewer-administered questionnaire for an average of 5 years following a diagnosis of occupational contact dermatitis. 48% had allergic contact dermatitis and 52% had irritant contact dermatitis. There was a poor correlation between the workers' recalled diagnosis and the actual diagnosis, but better concordance with their recollection of patch test results. Only 33% correctly identified their diagnosis. Those who could not were approximately 2 x as likely to still have active dermatitis, to have more severe dermatitis and to note that their skin problem interfered with their work and home activities. Those who had no idea of their diagnosis were 3 x as likely to have these problems. These results raise the possibility that further efforts directed at the patient's education with respect to their condition might improve the outcome of their occupational skin disease.

Adult↗
PubMed1991

A proportionate mortality study on risk of bladder cancer among rubber workers.

A proportionate mortality study was based on a sample of 6208 workers who were employed for at least 4 months during the period from 1917 to 1983 in a rubber tire manufacturing plant in Ontario, Canada. Identifying information of the workers was extracted from company records and linked to the Ontario Cancer Registry 1964-1983 death files. Among the cohort, 153 cancer deaths (146 male, 7 female), which included 6 bladder cancer deaths (all male), were found. For the six bladder cancer deaths, average age at time of first employment was 33.5 years, and average time from first employment to time of death was 31.8 years (with a range from 25.3 to 38.3 years). Proportionate mortality ratio (PMR) and mortality odds ratio (MOR), and their standardized forms (SPMR and SMOR), were calculated using the general population in Ontario for comparison. PMR and MOR were found to be 1.44 and 1.45, respectively. When the Ontario proportionate cancer mortality was applied to the cohort, adjusted for age and sex, 4.69 bladder cancer deaths were expected. The six bladder cancer deaths among the rubber workers therefore represented a 1.28-fold increase in standardized proportionate bladder cancer mortality when compared to the general population. Age and sex adjusted SMOR was found to be 1.29.

Carcinogens↗
PubMed1990

Methylchloroisothiazolinone-methylisothiazolinone reactions in patients screened for vehicle and preservative hypersensitivity.

More than 1100 patients were tested with methylchloroisothiazolinone-methylisothiazolinone, 100 ppm, in aqueous and petrolatum-based patch test materials from 1985 to 1987 by members of the North American Contact Dermatitis Group. Thirteen reactions to the aqueous materials and 10 to the petrolatum-based materials were observed. Irritant reactions were infrequent, and about half the reactions were deemed relevant. From 1984 to 1985, patch tests with this substance at a concentration of 250 ppm in petrolatum were conducted. Thirteen persons were identified as allergic, but three others were sensitized by the patch test procedure. Sensitization as not observed in tests with aqueous or petrolatum-based substance at a concentration of 100 ppm, and this concentration appears to be the best compromise between safety and sensitive detection of allergy. Use tests are helpful but not infallible as a guide in establishing relevance with methylchloroisothiazolinone-methylisothiazolinone. Wash-off products are frequently well tolerated by patients with positive reactions to this substance.

Adult↗