Percutaneous reactivity to natural rubber latex proteins persists in health-care workers following avoidance of natural rubber latex

Occupational rhinitis and occupational asthma: Association or progression?

BACKGROUND

Occupational asthma is the most frequently reported occupational respiratory disease in registries, and is often co-diagnosed with occupational rhinitis. We undertook a systematic review of the English-language epidemiologic literature linking these two conditions, with emphasis on progression from occupational rhinitis to occupational asthma.

METHODS

PubMed and Embase were queried in a series of structured searches designed to identify studies comparing occupational asthma and occupational rhinitis incidence or prevalence in occupationally exposed individuals.

RESULTS

The searches yielded a total of 109 unique citations, 15 of which yielded inferential data on the occupational rhinitis-asthma relationship. Nine of fifteen studies showed statistically significant associations between the occurrence of occupational rhinitis and occupational asthma among individual workers.

CONCLUSIONS

Limited data support the notion that occupational rhinitis precedes the development of occupational asthma, particularly when high-molecular-weight (HMW) agents are involved. The relationship between the two conditions could not be evaluated in many relevant studies due to a lack of cross-tabulation of individual cases.

Occupational Latex Allergy: the Current State of Affairs

PURPOSE OF REVIEW

Allergy to natural rubber latex (NRL) reached epidemic proportions during the nineties and led to intense preventive efforts. The aim of this review was to provide a comprehensive compilation of the current status of occupational NRL allergy.

RECENT FINDINGS

Recent advances led to the characterization of 15 NRL allergens and the development of assays for measuring the allergen content of NRL materials and specific IgE antibodies against NRL allergen components. Preventive measures aimed at reducing workplace exposure to NRL allergens were associated with decreasing incidence rates of NRL allergy. However, a pooled analysis of epidemiological surveys published during the last 10 years provided prevalence estimates of NRL sensitization and allergy similar to those derived from studies conducted before 2003. Substantial progress has been made in the understanding and prevention of NRL allergy, although the disease may still remain a worldwide cause of concern.

Occupational management of type I latex allergy

BACKGROUND

Although the incidence of type 1 latex allergy has decreased in recent years with the introduction of powder-free low-protein (PFLP) latex gloves, type 1 latex allergy is still commonly found among workers who use natural rubber latex (NRL) gloves at work.

AIMS

To elucidate the optimal management of workers with type 1 latex allergy whose work necessitates the use of NRL gloves in the workplace.

METHODS

A sensitive electronic search of relevant bibliographic databases was performed with related search terms for articles from 1 January 1990 to 1 September 2010. Relevant abstracts were reviewed, and studies that furnished data on the management of type 1 latex allergy in the workplace were extracted. Articles for inclusion in the review were appraised using the Scottish Intercollegiate Guideline Network methodology.

RESULTS

A total of 7041 abstracts were retrieved; 12 articles met the inclusion criteria for the review. We found moderately strong and consistent evidence that avoidance of NRL in the workplace reduces both symptoms and markers of sensitization in latex-allergic individuals. There is limited evidence that latex-allergic workers can continue to use PFLP gloves with no worsening of symptoms, provided that their co-workers also use PFLP latex or non-latex gloves.

CONCLUSIONS

Individuals with type 1 latex allergy whose work necessitates them wearing latex gloves may continue in their job provided that adjustments are made to ensure that they are not exposed to powdered latex gloves.

The prevalence of latex sensitisation and allergy and associated risk factors among healthcare workers using hypoallergenic latex gloves at King Edward VIII Hospital, KwaZulu-Natal South Africa: a cross-sectional study

OBJECTIVES

The present study describes latex sensitisation and allergy prevalence and associated factors among healthcare workers using hypoallergenic latex gloves at King Edward VIII Hospital in KwaZulu-Natal, South Africa.

DESIGN

Cross-sectional study.

SETTING

A tertiary hospital in eThekwini municipality, KwaZulu-Natal, South Africa.

PARTICIPANTS

600 healthcare workers were randomly selected and 501 (337 exposed and 164 unexposed) participated. Participants who were pregnant, with less than 1 year of work as a healthcare worker and a history of anaphylactic reaction were excluded from the study.

PRIMARY AND SECONDARY OUTCOME MEASURES

Latex sensitisation and latex allergy were the outcome of interest and they were successfully measured.

RESULTS

The prevalence of latex sensitisation and allergy was observed among exposed workers (7.1% and 5.9%) and unexposed workers (3.1% and 1.8%). Work-related allergy symptoms were significantly higher in exposed workers (40.9%, p<0.05). Duration of employment was inversely associated with latex allergy (OR 0.9; 95% CI 0.8 to 0.9). The risk of latex sensitisation (OR 4.2; 95% CI 1.2 to 14.1) and allergy (OR 5.1; 95% CI 1.2 to 21.2) increased with the exclusive use of powder-free latex gloves. A dose-response relationship was observed for powdered latex gloves (OR 1.1; 95% CI 1.0 to 1.2). Atopy (OR 1.5; 95% CI 0.7 to 3.3 and OR 1.4; 95% CI 0.6 to 3.2) and fruit allergy (OR 2.3; 95% CI 0.8 to 6.7 and OR 3.1; 95% CI 1.1 to 9.2) also increased the risk of latex sensitisation and allergy.

CONCLUSIONS

This study adds to previous findings that healthcare workers exposed to hypoallergenic latex gloves are at risk for developing latex sensitisation highlighting its importance as an occupational hazard in healthcare. More research is needed to identify the most cost effective way of implementing a latex-free environment in resource-limited countries, such as South Africa. In addition more cohort analysis is required to better understand the chronicity of illness and disability associated with latex allergy.

Microarray-based component-resolved diagnosis of latex allergy: isolated IgE-mediated sensitization to latexprofilin Hev b8 may act as confounder

Immediate type allergy to latex is still a widespread problem. Latex-allergic patients undergoing diagnostic and operative medical procedures are at risk of potentially life-threatening reactions. Accurate diagnostic methods are therefore crucial. The aim of this retrospective study was to discriminate between sensitization and relevant allergy to latex based on an easy and suitable diagnostic approach. In 14 patients with clinical symptoms and 27 controls, latex skin prick tests (SPT), IgE against latex (CAP) and serological component resolved specific latex-allergen determination (Hev b1, b3, b5, b6, b7, b8, b9, b10, b11) based on ImmunoCAP ISAC were performed. SPT correlated very well with clinically manifest latex-allergy demonstrating a high specificity (95%) (and a low sensitivity). However, CAP levels to crude latex could not safely discriminate between purely sensitized and latex-allergic patients. The majority of patients mono-sensitized to the latex profilin Hev b8 did not suffer from any relevant symptoms upon contact with latex. However, in two patients with latex-allergy diagnosed by elevated specific IgE only sensitized against Hev b8, additional sensitization to carbohydrate cross-reactive determinants (CCD) was found. In the case of positive serum IgE against latex and negative SPT, component-resolved diagnosis including IgE against specific latex-proteins, specially Hev b8, and carbohydrate cross-reactive determinants (CCD) is a useful tool to discriminate between latex-sensitization and latex-allergy.

Randomized, double-blind, placebo-controlled clinical trial of sublingual immunotherapy in natural rubber latex allergic patients

BACKGROUND

Natural rubber latex allergy is a common and unsolved health problem. Since the avoidance of exposure is very difficult, immunotherapy is strongly recommended, but before its use in patients, it is essential to prove the efficacy and safety of extracts.The aim of the present randomised, double-blind, placebo-controlled clinical trial was to assess the efficacy and tolerability of latex sublingual immunotherapy in adult patients undergoing permanent latex avoidance.

METHODS

Twenty-eight adult latex-allergic patients (5 males and 23 females), with mean age of 39 years (range 24-57) were randomized to receive a commercial latex-sublingual immunotherapy or placebo during one year, followed by another year of open, active therapy. The following outcomes were measured at baseline and at the end of first and second year of follow-up: skin prick test, gloves-use score, conjunctival challenge test, total and specific IgE, basophil activation test, and adverse reactions monitoring.

RESULTS

No significant difference in any of the efficacy in vivo variables was observed between active and placebo groups at the end of the placebo-controlled phase, nor when each group was compared with their baseline values at the end of the two year-study. An improvement in the average percentage of basophils activated was observed. During the induction phase, 4 reactions in the active group and 5 in the placebo group were recorded. During the maintenance phase, two patients dropped out due to pruritus and to acute dermatitis respectively.

CONCLUSION

Further studies are needed to evaluate latex-sublingual immunotherapy, since efficacy could not be demonstrated in adult patients with avoidance of the allergen.

TRIAL REGISTRATION NUMBER

ACTRN12611000543987.

Occupational rhinitis in bell pepper greenhouse workers: determinants of leaving work and the effects of subsequent allergen avoidance on health-related quality of life

BACKGROUND

Avoidance of occupational allergens or reduction in exposure has been advocated as the mainstay of the management of occupational rhinitis. Sparse data to the effect of allergen avoidance are available.

OBJECTIVE

To identify factors that may lead to leaving work and to address the effect of subsequent allergen avoidance on quality of life.

METHODS

A survey to the prevalence of occupational allergy to bell pepper performed in 1999 comprised 472 employees, of which 254 had work-related rhinitis and 228 completed the Rhinitis-related Quality of Life Questionnaire. After 8-year follow-up in 2007, 91 workers with rhinitis in 1999 were available to fill out the questionnaire again and were used to evaluate the course of nasal disease in terms of perceived severity and impact on daily life.

RESULTS

Workers with rhinitis at baseline were more likely to leave their job in bell pepper cultivation for another job (OR = 1.62, 95% CI 0.95-2.75). Among the 91 workers, 58 subjects were still at work, whereas 33 subjects had left work. The subjects who left jobs reported substantial improvement in quality of life. The magnitude of the changes ranged from -0.31 to -1. The effect of quitting work on the mean quality of life score amounted -0.76 ± 0.15.

CONCLUSIONS

The current study is the first large longitudinal studies showing that leaving work and subsequent occupational allergen avoidance have a beneficial effect on rhinitis-related quality of life. The study suggests that occupational rhinitis can be a reason to leave work.

Hev B 6.02 is the most important allergen in health care workers sensitized occupationally by natural rubber latex gloves

BACKGROUND

Natural rubber latex (NRL) allergy is a common occupational disease in health care workers (HCW). However, few reports have compared the major allergen of HCWs to those in gloves that are routinely used in the hospital. The aim of this study was to evaluate the major NRL allergens in gloves used by HCWs.

METHODS

We studied 20 HCWs who were suspected to have latex allergy (LA). We performed a skin prick test (SPT) using NRL allergens. Serological testing was performed using the ImmunoCAPTM. The total amount of protein and the antigenic protein concentrations extracted from NRL gloves were measured. Four different types of FITkitTM were used to measure the concentrations of Hev b 1, 3, 5, and 6.02 in the gloves.

RESULTS

A SPT using NRL extract identified 14 cases with positive reactions. The sensitivity and specificity of the SPT scores to the NRL glove extract were 100%. The sensitivity of latex specific IgE was 100% but the specificity was 14.2%. The sensitivity and specificity of rHev b 6.02 specific IgE were 100% in the LA group. The total amounts of protein from the medical gloves for surgery and examination were 265 microg/g and 95 microg/g, respectively. The antigenic protein concentrations in the gloves were 24.9 microg/g and 1.0 microg/g, respectively. The total amounts of the specific four allergens in the NRL gloves were 2.18 microg/g and 0.45 microg/g, respectively.

CONCLUSIONS

We concluded that the main allergen of HCWs who have been sensitized occupationally by NRL gloves was Hev b 6.02.