Occupational asthma and rhinoconjunctivitis induced by natural rubber latex exposure

Latex Allergy - From Discovery to Component-resolved Diagnosis

Latex allergy is a hypersensitivity response to natural rubber latex (NRL) proteins or rubber chemicals used in the manufacture of latex products. An accurate diagnosis is the first step in the effective management of individuals with latex allergy, especially in high-risk groups, such as healthcare workers and those affected by spina bifida. Diagnosis is based on the clinical history and an accurate allergological evaluation. In the case of type I IgE-mediated hypersensitivity reactions, which can manifest urticaria, angioedema, rhinoconjunctivitis, asthma and anaphylaxis after latex exposure, skin prick tests or latex-specific IgE (sIgE) antibody detection using serological assays can be performed to confirm sensitization. Instead, in the case of contact dermatitis, a patch test can be applied to confirm the presence of a type IV T cell-mediated hypersensitivity reaction to rubber accelerators or additives. Basophils activation tests or challenge tests may be performed if there's an incongruity between the clinical history and the results of in vivo and in vitro tests. The aim of this review is to analyze the current state of the art of diagnostic techniques for latex allergy and algorithms employed in clinical practice and possible future developments in this field.

ICON: Diagnosis and management of allergic conjunctivitis

Ocular allergy (OA), interchangeably known as allergic conjunctivitis, is a common immunological hypersensitivity disorder affecting up to 40% of the population. Ocular allergy has been increasing in frequency, with symptoms of itching, redness, and swelling that significantly impacts an individual's quality of life (QOL). Ocular allergy is an often underdiagnosed and undertreated health problem, because only 10% of patients with OA symptoms seek medical attention, whereas most patients manage with over-the-counter medications and complementary nonpharmacological remedies. The clinical course, duration, severity, and co-morbidities are varied and depend, in part, on the specific ocular tissues that are affected and on immunologic mechanism(s) involved, both local and systemic. It is frequently associated with allergic rhinitis (commonly recognized as allergic rhino conjunctivitis), and with other allergic comorbidities. The predominance of self-management increases the risk of suboptimal therapy that leads to recurrent exacerbations and the potential for development of more chronic conditions that can lead to corneal complications and interference with the visual axis. Multiple, often co-existing causes are seen, and a broad differential diagnosis for OA, increasing the difficulty of arriving at the correct diagnosis(es). Ocular allergy commonly overlaps with other anterior ocular disease disorders, including infectious disorders and dry eye syndromes. Therefore, successful management includes overcoming the challenges of underdiagnosis and even misdiagnosis by a better understanding of the subtleties of an in-depth patient history, ophthalmologic examination techniques, and diagnostic procedures, which are of paramount importance in making an accurate diagnosis of OA. Appropriate cross-referral between specialists (allergists and eyecare specialists) would maximize patient care and outcomes. This would significantly improve OA management and overcome the unmet needs in global health.

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.

Identification and practical management of latex allergy in occupational settings

Allergy to natural rubber latex (NRL) from Hevea brasiliensis is a relevant occupational health hazard. The use of gloves and products manufactured with latex and environmental allergen exposure in the work environment are risks factors for the development of occupational allergy among different job categories. Healthcare workers have been the most commonly affected, but other professions with exposure to latex products such as hairdressers, cleaners, food handlers and those making natural rubber latex (NRL) products are also at risk of developing occupational allergy. Clinical manifestations of IgE-mediated latex allergy can range from troublesome skin disorders to life-threatening systemic reactions. It is very important to identify the occupational allergic diseases in their early stages in order to implement avoidance strategies. For this purpose, the interventions for prevention should emphasize the importance of latex allergy awareness and surveillance among exposed workforces.

Respiratory effects among rubberwood furniture factory workers in Thailand

Respiratory symptoms and pulmonary function were examined among 89 rubberwood furniture factory workers. Acute and chronic irritant symptoms were assessed, lung function was measured both pre- and post-shift and personal inhalable dust exposure determined. The only symptoms with a significant increase among high dust level-exposed workers (>1 mg/m(3)) were those related to nasal irritation. High dust level-exposed workers had a significant cross-shift decrease in forced expiratory volume in 1 second/forced vital capacity (FEV(1)/FVC) compared with low dust level-exposed workers and increases in inhalable dust concentration levels (mg/m(3)) were significantly associated with decreases in the peak expiratory flow (PEF) across the work shift. For percent predicted pulmonary function levels, a significant decrement in PEF was found for high versus low rubberwood dust level-exposed workers, after controlling for confounders. These findings suggest the need for an occupational standard for rubberwood dust in Thailand.

Risk factors associated with asthma phenotypes in dental healthcare workers

BACKGROUND

Exposure in the dental environment can increase the risk of respiratory disease in dental healthcare workers (HCWs). This study investigated the prevalence of asthma phenotypes in dental HCWs and associated risk factors.

METHODS

A cross-sectional study of 454 dental HCWs in five dental institutions in South Africa was conducted. A self-administered questionnaire elicited the health and employment history of subjects. Sera was analyzed for atopic status and latex sensitization. Pre- and post-bronchodilator spirometry was performed.

RESULTS

The prevalence of atopic asthma was 6.9%, non-atopic asthma 5.9% and work-exacerbated asthma (WEA) 4.0%. Atopy and work-related ocular-nasal symptoms were strong predictors of WEA (OR: 3.4; 95% CI: 1.07-10.8; OR: 6.7, 95% CI: 2.4-19.1), respectively. Regular use of personal protective equipment (PPE) was associated with a protective affect (OR: 0.23, 95% CI: 0.1-0.7) among non-atopic asthmatics, while glove use and respiratory protection was protective among atopic asthmatics (OR: 0.39, 95% CI: 0.17-0.89).

CONCLUSION

Identification of risk factors associated with specific asthma phenotypes in dental HCWs can be used to focus preventive strategies for asthmatics.

Off-label use of omalizumab in non-asthma conditions: new opportunities

Allergic diseases are mediated by IgE and, hence, neutralizing IgE to attenuate type I hypersensitivity reactions may result in clinical benefits. This has been mainly established in several large pre- and postmarketing studies of the humanized monoclonal anti-IgE antibody, omalizumab, in patients with allergic asthma. In this patient population, omalizumab has been shown to have beneficial effects in subjective and objective outcome measures, as well as resulting in reductions in medication use. Omalizumab is now globally licensed for use in severe persistent asthma. However, a growing number of reports suggest that anti-IgE treatment may also be beneficial to patients suffering from other IgE-related conditions, including allergic rhinitis, peanut allergy, latex sensitivity, atopic dermatitis, chronic urticaria and allergic bronchopulmonary aspergillosis. For these patients, and specifically for those with severe refractory disease, anti-IgE treatments might have the potential of reducing their financial burden both in terms of medical costs and of loss of productivity in missed work and school days. In this reveiw, we evaluate the evidence in support of a more extensive role for omalizumab in a number of non-asthma IgE-related conditions, and particularly where intensive treatment has not been effective. However, studies with larger numbers of well-characterized patients will be necessary to provide sound evidence regarding the benefit of IgE blockade in these challenging conditions.

Alergia ao látex em profissionais de saúde de São Paulo, Brasil

FUNDAMENTOS: Alergia ao látex é comum em trabalhadores da saúde, resultando em absenteísmo e afastamento das atividades profissionais. Há no Brasil poucos estudos publicados sobre o assunto. Enquanto na população geral a prevalência de alergia ao látex é menor que 2%, nos profissionais de saúde pode chegar a 30%. OBJETIVO: Estudar a prevalência de alergia ao látex em profissionais de saúde do Hospital do Servidor Público Estadual de São Paulo. MÉTODOS: Foi aplicado questionário aberto a profissionais que têm contato com luvas de borracha em todos os serviços do hospital. Foi colhido sangue daqueles que referiram sintomas e dosado anticorpo IgE específico por meio do ImmunoCAP. Para análise estatística utilizaram-se porcentagens, tabelas e teste qui-quadrado. RESULTADOS: Foram distribuídos 2.349 questionários, e respondidos 1.045, dos quais 129 referiram correlação entre uso de látex e sintomas sugestivos de alergia, e 54 permitiram a coleta de sangue para determinação de IgE específica. Neste grupo houve dois casos em que foi demonstrado anticorpo específico, estabelecendo-se prevalência de 3,7% de alergia ao látex. Fatores como gênero, profissão, freqüência de contato com luvas, setor de trabalho e antecedentes de atopia foram relacionados com maior prevalência de alergia ao látex. CONCLUSÃO: A prevalência de alergia ao látex encontrada foi de 3,7%.

Anti-IgE antibodies for the treatment of IgE-mediated allergic diseases

The pharmacological purposes of the anti-IgE therapy are to neutralize IgE and to inhibit its production to attenuate type I hypersensitivity reactions. The therapy is based on humanized IgG1 antibodies that bind to free IgE and to membrane-bound IgE on B cells, but not to IgE bound by the high-affinity IgE.Fc receptors on basophils and mast cells or by the low-affinity IgE.Fc receptors on B cells. After nearly 20 years since inception, therapeutic anti-IgE antibodies (anti-IgE) have been studied in about 30 Phase II and III clinical trials in many allergy indications, and a lead antibody, omalizumab, has been approved for treating patients (12 years and older) with moderate-to-severe allergic asthma. Anti-IgE has confirmed the roles of IgE in the pathogenesis of asthma and helped define the concept "allergic asthma" in clinical practice. It has been shown to be safe and efficacious in treating pediatric allergic asthma and treating allergic rhinitis and is being investigated for treating peanut allergy, atopic dermatitis, latex allergy, and others. It has potential for use to combine with specific and rush immunotherapy for increased safety and efficacy. Anti-IgE thus appears to provide a prophylactic and therapeutic option for moderate to severe cases of many allergic diseases and conditions in which IgE plays a significant role. This chapter reviews the evolution of the anti-IgE concept and the clinical studies of anti-IgE on various disease indications, and presents a comprehensive analysis on the multiple intricate immunoregulatory pharmacological effects of anti-IgE. Finally, it reviews other approaches that target IgE or IgE-expressing B cells.

Prevalence and determinants of asthma in adult male leather tannery workers in Karachi, Pakistan: a cross sectional study

Background

This study aimed to estimate the prevalence and to identify some risk factors of adult asthma in male leather tannery workers in Karachi, Pakistan.

Methods

A cross sectional study was conducted from August 2003 to March 2004 on leather tannery workers of Karachi, Pakistan. Data were collected from 641 workers engaged in 95 different tanneries in Korangi industrial area selected as sample of convenience. Face to face interviews were performed using a structured pre-tested questionnaire by trained data collectors.

Results

Prevalence of adult asthma was 10.8% (69/641) in this study population. The prevalence of perceived work-related asthma was 5.3% (34/641). Multivariable logistic regression model showed that after taking into account the age effect, the leather tannery worker were more likely to be asthmatic, if they were illiterate (adjusted OR = 2.13, 95% CI: 1.17–3.88), of Pathan ethnicity (adjusted OR = 2.69; 95% CI: 1.35–5.36), ever-smoked (adjusted OR = 2.22, 95% CI: 1.16–4.26), reportedly never used gloves during different tanning tasks (OR = 3.28; 95% CI : 1.72–6.26). Also, the final model showed a significant interaction between perceived allergy and duration of work. Those who perceived to have allergy were more likely to have asthma if their duration of work was 8 years (adjusted OR = 2.26; 95% CI: 1.19 – 4.29) and this relationship was even stronger if duration was 13 years (adjusted OR = 3.67; 95% CI: 1.98–6.79).

Conclusion

Prevalence of asthma in leather tannery workers appears to be high and is associated with educational status, ethnicity, smoking, glove use, perceived to have allergy and duration of work.

Differential expression of allergens on the internal and external surfaces of latex surgical gloves

BACKGROUND

Differences in latex allergen sensitization profiles have been described between children undergoing repeated surgical interventions and health care workers. The purpose of this study was to determine whether such sensitization profiles are associated with differences in the expression of latex allergen between the internal and external surfaces of surgical gloves.

METHODS

Extracts were obtained from whole surgical gloves as well as from their external and internal surfaces. The extracts were centrifuged, filtered, concentrated, dialyzed and lyophilized. The protein profile of the extracts was analyzed using hydrophobic interaction chromatography (HIC) and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Immunoblotting was performed using sera from two patients with confirmed latex allergy. Latex recombinant allergen-specific IgE in these two patients was determined using a fluorescence enzyme immunoassay (FEIA) method. Latex allergen quantification was determined on both glove surfaces using an ELISA method.

RESULTS

HIC and SDS-PAGE showed qualitative and quantitative differences in proteins between the internal and external glove surfaces, with the former being much richer in proteins. Immunoblotting of glove extracts using sera from two latex-allergic health workers showed differences between glove surface extracts. ELISA quantification of latex allergens demonstrated that the internal glove surface had high amounts of Hev b 5 and Hev b 6.02 whereas the external surface showed Hev b 1, Hev b 3, and Hev b 6.02.

CONCLUSIONS

Our results reveal substantial differences in the composition of latex allergen profiles between the internal and external surfaces of surgical latex gloves, which may suggest a relationship between latex allergen localization and sensitization routes in different risk groups.

Cutaneous, but not airway, latex exposure induces allergic lung inflammation and airway hyperreactivity in mice

As respiratory symptoms are common in addition to skin reactions in natural rubber latex allergy, we investigated the significance of different allergen exposure routes in the development of lung inflammation and airway hyperreactivity (AHR). Both intracutaneous (IC) and intraperitoneal (IP) exposure followed by airway challenge with latex proteins induced an influx of mononuclear cells and eosinophils to the lungs. AHR and lung mucus production increased significantly after IC and IP but not after intranasal (IN) exposure. Infiltration of inflammatory cells was associated with the induction of T-helper type 2 (Th2) cytokines and several CC chemokines. Only a marginal induction of these mediators was found after IN exposure. On the contrary, increased levels of transforming growth factor-beta1 and forkhead box 3 mRNA, markers of regulatory activities, were found in the lungs after IN but not after IC exposure. Finally, IC and IP, but not IN, latex exposure induced a striking increase in specific immunoglobulin E (IgE) levels. Cutaneous latex exposure in the absence of adjuvant followed by airway challenge induces a local Th2-dominated lung inflammation and a systemic IgE response. Cutaneous exposure to proteins eluting from latex products may therefore profoundly contribute to the development of asthma in latex allergy.

Occupation-related allergies in dentistry

BACKGROUND

Allergies to natural rubber latex (NRL) were unknown in dentistry until 1987. That changed with the publication of a report documenting NRL-based anaphylaxis in a dental worker. This case and others prompted regulatory and manufacturing changes in rubber products and increased awareness throughout the profession. However, other common dental chemicals cause allergic reactions and irritation and often are handled with insufficient precautions. Although recognition of NRL allergy has improved, awareness of other potential allergens and irritants in dentistry still is limited.

OVERVIEW

Recent research indicates that the prevalence of NRL protein allergy may be decreasing. In contrast, occupation-related dermatoses associated with other dental products may be more common. Encounters with bonding agents, disinfectants, rubber, metals and detergents can cause occupation-based irritant contact dermatitis and allergic contact dermatitis. These conditions may be found in more than one-quarter of dental and medical personnel. Therefore, dental-specific information about the recognition and management of allergic and irritant reactions is needed.

CONCLUSIONS AND CLINICAL IMPLICATIONS

The prevalence of occupation-related dermatitis may be increasing in dentistry. Reducing exposure to potential irritants and allergens and educating personnel about proper skin care are essential to reversing this trend.

Occupational exposures as triggers of asthma

The prevalence of occupational asthma is rising, possibly due to the introduction of different chemicals and substances in the workplace. Etiologic agents include organic and inorganic compounds that are encountered in a variety of industries. Early diagnosis, adequate management of inflammation, and prevention of further exposure are essential to occupational asthma management. Reducing complications and disability while providing work rehabilitation should be the ultimate goal of the health care provider. This article discusses these issues and gives guidance to the clinician treating patients with possible occupational asthma.

Occupational asthma and rhinitis induced by a herbal medicine, Wonji (Polygala tenuifolia)

Occupational asthma is induced by many agents, including herbal materials, that are exposed in working places. Although there are a few case reports for occupational allergy induced by herbal materials, there is none for that induced by Wonji (Polygala tenuifolia). This study was conducted to evaluate clinical characteristics and immunologic mechanism of Wonji-induced asthma in a exposed-worker. A patient who complained of asthma and rhinitis symptoms, and who had worked in a herbal manufacturing factory for 8 yr, underwent a skin prick test with crude extract of Wonji under the impression of occupational asthma induced by the agent. The patient had a strong positive response to the extract on the skin prick test. Allergen bronchial challenge to the extract demonstrated a typical dual response. Serum specific IgE level to the extract was higher in the patient than in healthy controls, and ELISA inhibition test revealed complete inhibition of IgE binding with the extract, but no inhibition with Der p 2 or mugwort extracts. Six IgE binding components to the extract (10, 25, 28, 36, 50, and 90 kDa) were detected using SDS-PAGE and immunoblot analysis. These findings suggest that Polygala tenuifolia, a herbal material, can induce IgE-mediated bronchoconstriction in exposed workers.

Latex allergy: diagnosis and management

Latex allergy is an IgE-mediated immediate hypersensitivity response to natural rubber latex (NRL) protein with a variety of clinical signs ranging from contact urticaria, angioedema, asthma, and anaphylaxis. Major allergens include dipped latex products such as gloves and balloons. In highest risk for NRL allergy are patients with spina bifida, but health care workers and others who wear latex gloves are also at risk. NRL allergic patients may also react to fruits/foods, especially banana, kiwi, and avocado. Diagnosis is made by a positive latex RAST and/or skin prick test or challenge test to NRL. Allergen avoidance and substitution and the use of latex-safe devices including synthetic gloves (vinyl, synthetic polyisoprene, neoprene, nitrile, block polymers, or polyurethane) are essential for the affected patient. Accommodation in the workplace may include the use of powder-free, low-allergen NRL gloves or synthetic gloves. These preventive measures have significantly reduced the prevalence of reported reactions to NRL. Hyposensitization is not yet feasible.

A Review of Natural‐Rubber Latex Allergy in Health Care Workers

This brief review of natural-rubber latex (NRL) allergy in health care workers (HCWs) includes the definition of NRL allergy and data on its epidemiology, pathogenesis, diagnostic algorithm, management, long-term outcomes, economic impact, cost-effectiveness of changing facilities to a latex-free environment, and prevention. The data presented suggest that an individual with type I or type IV hypersensitivity to NRL should be able to continue to work in the workplace with careful evaluation and reasonable accommodations. Reducing exposure to latex is a safe and more economical alternative to complete removal of the individual from the place of employment. The use of low-allergen, nonpowdered NRL gloves substantially reduces airborne exposure to latex in most health care settings.

Occupational asthma caused by high-molecular-weight substances

More than 250 agents that are encountered in the workplace have been shown to induce asthma in susceptible individuals. It is estimated that 2% to 15% of cases of asthma may be occupational. High-molecular-weight substances, such as plant and animal proteins, enzymes, and large carbohydrate molecules, can induce IgE-mediated occupational asthma. The incidence of disease varies among industries and is dependent on the physiochemical properties of the agent, the level and duration of exposure, industrial hygiene, engineering practices, and host factors. Risk factors, common high-molecular-weight workplace antigens, diagnosis, treatment, and prognosis are discussed.

Differential diagnosis of occupational asthma

Confidently establishing the diagnosis of occupational asthma (OA) is a complicated undertaking, because it requires that the patient's asthma symptoms are caused exclusively (or at least in large part) by occupational exposures. Asthma is a common disease, and the differential diagnosis of asthma is a frequently discussed subject that includes common and uncommon disorders. This article presents a broad characterization of OA, including the elements necessary to establish a diagnosis. Differential diagnosis also is discussed.

Occupational allergies caused by latex

Allergy to natural rubber latex is an important cause of occupational allergy in healthcare workers. Disposable medical gloves are the major reservoir of latex allergens, particularly powdered gloves, in healthcare delivery settings. Diagnosis of latex allergy requires a history of exacerbation of cutaneous, respiratory, ocular, or systemic signs and symptoms after exposure to natural rubber latex products; and evidence of sensitization by patch testing, skin testing, measurement of latex-specific IgE antibodies, or challenge testing. Optimal management of latex allergy involves education concerning cross-reacting allergens, reduction of cutaneous or mucosal contact with dipped rubber products, and minimization of exposure to latex aeroallergens in work environments.