Airway Diseases Related to the Use of Cleaning Agents in Occupational Settings

Exposure to disinfectants and cleaning products (DCPs) is now a well-established risk factor for work-related asthma (WRA). However, questions remain on the specific causal agents and pathophysiological mechanisms. Few studies have also reported an association between DCPs and rhinitis or chronic obstructive pulmonary disease. This review discusses the recent evidence pertaining to airway diseases attributable to occupational exposure to DCPs. In contrast to other agents, the incidence of WRA due to DCPs has increased over time. The use of DCPs in spray form has clearly been identified as an added risk factor. The mechanisms for WRA associated with DCPs remain poorly studied; however, both allergic and nonallergic responses have been described, with irritant mechanisms thought to play a major role. An early diagnostic workup based on clinical assessment accompanied by evaluation of lung function and immunological and airway inflammatory markers is important to guide optimal care and exposure avoidance to the implicated agent. Future research should focus on the effects of "green" products, pathophysiological mechanisms, and quantitative exposure assessment including the use of barcode-based methods to identify specific agents. There is an urgent need to strengthen preventive measures and interventions to reduce the burden of airway diseases associated with DCPs.

How Allergists Can Perform an Occupational History in Every Patient

The occupational history is often neglected in the routine evaluation of new patients with asthma, chronic rhinitis, or dermatologic complaints. Such omissions are inadvertent because work-related conditions are often not prioritized. There also may be lack of awareness of the scope of respiratory or cutaneous allergens capable of inducing occupational asthma (OA) or work-related contact dermatitis. Evidence exists suggesting that the occupational history is often neglected among primary care physicians and specialists. Failure to diagnose OA in a timely fashion by identifying occupational sources of exposure, for example, may result in unnecessary morbidity in workers whose exposure is not modified. In this commentary, we propose a brief intake survey to be administered to all patients coming to an allergy practice to quickly screen for possible work-related respiratory symptoms and another for occupational dermatitis. This would require minimal physician time and could be self-administered at the initial encounter and incorporated into the medical record. A positive response to either survey should trigger a more detailed evaluation by the allergy specialist. More detailed approaches for stepwise clinical evaluation of the worker suspected of OA and contact dermatitis are discussed.

Diagnostic Accuracy of Specific IgE Against Wheat and Rye in Flour-Induced Occupational Asthma

BACKGROUND

Assessment of IgE-mediated sensitization to flour allergens is widely used to investigate flour-induced occupational asthma. The diagnostic efficiency of detecting specific IgE antibodies (sIgEs) against wheat and rye flour, however, has not been thoroughly compared with other diagnostic procedures.

OBJECTIVE

We sought to evaluate the diagnostic accuracy of sIgE against wheat and rye compared with specific inhalation challenge (SIC) with flour as the reference standard.

METHODS

This retrospective multicenter study included 264 subjects who completed an SIC with flour in eight tertiary centers, of whom 205 subjects showed a positive SIC result.

RESULTS

Compared with SIC, sIgE levels of 0.35 kUA/L or greater against wheat and rye provided similar sensitivities (84% to 85%, respectively), specificities (71% to 78%), positive predictive values (91% to 93%), and negative predictive values (56% to 61%). Increasing the threshold sIgE value to 5.10 kUA/L for wheat and to 6.20 kUA/L for rye provided a specificity of 95% or greater and further enhanced the positive predictive value to 98%. Among subjects with a positive SIC, those who failed to demonstrate sIgE against wheat and rye (n = 26) had significantly lower total serum IgE level and blood and sputum eosinophil counts and a lesser increase in postchallenge FeNO compared with subjects with a detectable sIgE.

CONCLUSION

High levels of sIgE against wheat and/or rye flour strongly support a diagnosis of flour-induced occupational asthma without the need to perform an SIC. The absence of detectable sIgE against wheat and rye in subjects with a positive SIC seems to be associated with lower levels of TH2 biomarkers.

Comparison of high- and low-molecular-weight sensitizing agents causing occupational asthma: an evidence-based insight

INTRODUCTION

The many substances used at the workplace that can cause sensitizer-induced occupational asthma are conventionally categorized into high-molecular-weight (HMW) agents and low-molecular-weight (LMW) agents, implying implicitly that these two categories of agents are associated with distinct phenotypic profiles and pathophysiological mechanisms.

AREAS COVERED

The authors conducted an evidence-based review of available data in order to identify the similarities and differences between HMW and LMW sensitizing agents.

EXPERT OPINION

Compared with LMW agents, HMW agents are associated with a few distinct clinical features (i.e. concomitant work-related rhinitis, incidence of immediate asthmatic reactions and increase in fractional exhaled nitric oxide upon exposure) and risk factors (i.e. atopy and smoking). However, some LMW agents may exhibit 'HMW-like' phenotypic characteristics, indicating that LMW agents are a heterogeneous group of agents and that pooling them into a single group may be misleading. Regardless of the presence of detectable specific IgE antibodies, both HMW and LMW agents are associated with a mixed Th1/Th2 immune response and a predominantly eosinophilic pattern of airway inflammation. Large-scale multicenter studies are needed that use objective diagnostic criteria and assessment of airway inflammatory biomarkers to identify the pathobiological pathways involved in OA caused by the various non-protein agents.

Multivariate analysis and data mining help predict asthma exacerbations

BACKGROUND

Work-related asthma has become a highly prevalent occupational lung disorder.

OBJECTIVE

Our study aims to evaluate occupational exposure as a predictor for asthma exacerbation.

METHOD

We performed a retrospective evaluation of 584 consecutive patients diagnosed and treated for asthma between October 2017 and December 2019 in four clinics from Western Romania. We evaluated the enrolled patients for their asthma control level by employing the Asthma Control Test (ACT < 20 represents uncontrolled asthma), the medical record of asthma exacerbations, occupational exposure, and lung function (i.e. spirometry). Then, we used statistical and data mining methods to explore the most important predictors for asthma exacerbations.

RESULTS

We identified essential predictors by calculating the odds ratios (OR) for the exacerbation in a logistic regression model. The average age was 45.42 ± 11.74 years (19-85 years), and 422 (72.26%) participants were females. 42.97% of participants had exacerbations in the past year, and 31.16% had a history of occupational exposure. In a multivariate model analysis adjusted for age and gender, the most important predictors for exacerbation were uncontrolled asthma (OR 4.79, p < .001), occupational exposure (OR 4.65, p < .001), and lung function impairment (FEV1 < 80%) (OR 1.15, p = .011). The ensemble machine learning experiments on combined patient features harnessed by our data mining approach reveal that the best predictor is professional exposure, followed by ACT.

CONCLUSIONS

Machine learning ensemble methods and statistical analysis concordantly indicate that occupational exposure and ACT < 20 are strong predictors for asthma exacerbation.

Recent developments in occupational asthma

PURPOSE OF REVIEW

Occupational asthma (OA) is a complex condition that can be difficult to diagnose. The purpose of this review is to describe some recent findings regarding the epidemiology of OA, the occupational sensitizing agents, the prognosis of OA, and its primary prevention.

RECENT FINDINGS

The risk of developing OA varies according to the geographic localization of the worker, the type of industry and the type of sensitizing agents. New findings have been reported for several known sensitizing agents, such as isocyanates, seafood & cleaning agents, and their related industries, such as hairdressing salons and schools. Moreover, a few new sensitizing agents, such as cannabis, have been identified in the past few years. The prognosis of OA seems worse than that of nonwork-related asthma. It is mainly determined by the duration and the level of exposure. Primary prevention is crucial to reduce the number of new cases of OA. Complete avoidance of exposure to the causal agent remains the optimal treatment of sensitizer-induced OA.

SUMMARY

Improving our knowledge regarding OA and its causative agents is key to enable an early recognition of this condition and improve its prognosis. Further research is still needed to improve primary prevention.

Sputum Inflammatory Patterns Are Associated With Distinct Clinical Characteristics in Patients with Occupational Asthma Independently of the Causal Agent

BACKGROUND AND OBJECTIVES

Background: Clinical heterogeneity in sensitizer-induced occupational asthma (OA) and its relationship to airway inflammatory profiles remain poorly elucidated. Objectives: To further characterize interactions between induced sputum inflammatory patterns, asthma-related outcomes, and the high- or low-molecular-weight category of causal agents in a large cohort of patients with OA.

METHODS

We conducted a multicenter, retrospective, cross-sectional study of 296 patients with OA confirmed by a positive specific inhalation challenge who completed induced sputum assessment before and 24 hours after challenge exposure.

RESULTS

Multivariate logistic regression analysis revealed that sputum eosinophilia ≥3% was significantly associated with a high dose of inhaled corticosteroid (OR [95%CI], 1.31 [1.11 1.55] for each 250-μg increment in daily dose), short-acting ß2-agonist use less than once a day (3.54 [1.82-7.00]), and the level of baseline nonspecific bronchial hyperresponsiveness (mild, 2.48 [1.21-5.08]; moderate/severe, 3.40 [1.44-8.29]). Sputum neutrophilia ≥76% was associated with age (1.06 [1.01-1.11]), male sex (3.34 [1.29-9.99]), absence of corticosteroid use (5.47 [2.09-15.16]), use of short-acting ß2-agonists once or more a day (4.09 [1.71-10.01]), ≥2 severe exacerbations during the previous 12 months at work (4.22 [1.14-14.99]), and isolated early reactions during the specific inhalation challenge (4.45 [1.85-11.59]).

CONCLUSIONS

The findings indicate that sputum inflammatory patterns in patients with OA are associated with distinct phenotypic characteristics and further highlight the differential effects of neutrophils and eosinophils on asthma-related outcomes. These associations between inflammatory patterns and clinical characteristics share broad similarities with findings reported in nonoccupational asthma and are not related to the type of causal agent.

Endotypes of occupational asthma

PURPOSE OF REVIEW

To describe recent findings in endotyping occupational asthma by addressing the role of specific biomarkers.

RECENT FINDINGS

Studies on occupational asthma endotypes have focused on immune and inflammatory patterns associated with different occupational exposures to sensitizers or irritants.Sputum neutrophilia has been found in 58.5% patients with occupational asthma caused by high molecular weight (HMW) agents, and work-related dysphonia in patients with occupational asthma was described as associated with sputum neutrophilia too. Neutrophils have been associated also with irritant-induced asthma. The measurement of specific IgE has been confirmed as a valuable diagnostic tool in occupational asthma caused by HMW agents, on the contrary, for most low-molecular-weight agents, the presence of specific IgE has been proven in a small subset of affected workers. Fractional exhaled nitric oxide has been confirmed as a marker of type 2 (T2) inflammation in occupational asthma, mostly when induced by HMW agents (e.g. flour), and it has proved to be more sensitive than spirometry in measuring the efficacy of an intervention.MicroRNA-155 has been shown to contribute to airway inflammation in occupational asthma induced by toluene diisocyanate.

SUMMARY

Occupational asthma is heterogeneous, thus monitoring multiple biomarkers is crucial to understand, which inflammatory responses are prevalent.

Long-term outcome of occupational asthma with different etiology

PURPOSE OF REVIEW

This review summarizes the recent literature on the long-term outcome of sensitizer-induced and irritant-induced occupational asthma.

RECENT FINDINGS

Recent studies of sensitizer-induced occupational asthma show that after the offending exposure has ceased, most patients report at least partial relief of symptoms. However, in the long term, the diagnosis may negatively impact their careers, incomes, and quality of life. The studies also offer new insights into diisocyanate-induced occupational asthma phenotypes and asthma remission rates. One third of these cases were in remission in long-term after reduction or cessation of exposure. The long-term prognosis of irritant-induced occupational asthma was demonstrated to be poorer than sensitizer-induced occupational asthma. Older age, low fractional exhaled nitric oxide levels and uncontrolled asthma at the time of diagnosis predicted uncontrolled asthma in the long term in patients with irritant and low-molecular-weight sensitizer induced occupational asthma.

SUMMARY

Recent studies provide further evidence of the long-term outcome of different occupational asthma phenotypes and the factors that affect them. These findings help us identify patients at risk of poor asthma outcomes, who need close monitoring and support. It should also be borne in mind that occupational asthma diagnosis may have wider-ranging negative impacts on patients' lives.

Update on occupational allergy, including asthma, to soluble platinum salts

PURPOSE OF REVIEW

This review aims to evaluate recent literature on occupational platinum salt exposure and allergy and asthma in the context of existing evidence.

RECENT FINDINGS

A major recent development is that large quantitative platinum salt exposure datasets have become available and are finding applications in epidemiological studies. These exposure data are expected to lead to higher quality epidemiological studies focusing on exposure response relations, modifiers of exposure and sensitization risk. The exposure data might also improve medical referral advice as part of medical surveillance studies and contribute to improved evidence on the effectiveness of exposure referral.

SUMMARY

Hopefully, the availability of exposure databases form a stimulus for more exposure response studies and risk assessments leading to science based primary prevention approaches. The availability of more detailed exposure data can guide job transfer decisions in occupational clinical practice.

[An epidemiological and evolutionary profile of occupational asthma of Tunisian workers]

INTRODUCTION

This study aims to identify the epidemiological and occupational characteristics of patients with occupational asthma (OA) and to assess their clinical evolution and occupational outcomes.

METHODS

We carried out a descriptive epidemiological study over a period of five years (from 2012 to 2016) about the OA cases in the private sector reported in the Tunisian region of Zaghouan.

RESULTS

All in all, 165 OA cases were reported during the study period, representing an annual incidence of 733.3 cases per 1,000,000 workers in the private sector. Our study population was composed predominantly (85.5%) of women, whose mean age was 41.5±6.8years. More than three quarters of the affected persons were working in the automobile industry, and most illnesses (77%) were attributable to isocyanates. The mean time to onset of the respiratory symptoms was longer for low molecular weight agents (13.6±3.1years) compared to high molecular weight agents (12.0±3.9years) (P=0.0006). The majority of OA cases (66.7%) lost their jobs. Job loss was significantly more frequent among asthmatic women and workers with OA due to isocyanates. Among the 62 cases of OA for whom risk factors were eliminated, 45 nonetheless remained symptomatic.

CONCLUSION

Effective prevention strategies involving the various actors need to be implemented in work environments so as to reduce the frequency and the medico-legal repercussions of a disabling condition.

Identification of true chemical respiratory allergens: Current status, limitations and recommendations

Asthma in the workplace is an important occupational health issue. It comprises various subtypes: occupational asthma (OA; both allergic asthma and irritant-induced asthma) and work-exacerbated asthma (WEA). Current regulatory paradigms for the management of OA are not fit for purpose. There is therefore an important unmet need, for the purposes of both effective human health protection and appropriate and proportionate regulation, that sub-types of work-related asthma can be accurately identified and classified, and that chemical respiratory allergens that drive allergic asthma can be differentiated according to potency. In this article presently available strategies for the diagnosis and characterisation of asthma in the workplace are described and critically evaluated. These include human health studies, clinical investigations and experimental approaches (structure-activity relationships, assessments of chemical reactivity, experimental animal studies and in vitro methods). Each of these approaches has limitations with respect to providing a clear discrimination between OA and WEA, and between allergen-induced and irritant-induced asthma. Against this background the needs for improved characterisation of work-related asthma, in the context of more appropriate regulation is discussed.

Occupational asthma induced by fish exposure

Occupational asthma triggered by inhaling fish-derived aerosols is estimated to affect 2-8% of exposed individuals. This primarily affects workers in the fish processing industry. Fishmongers, rarely experience this issue, as recent research found no significant difference in asthma rates compared to a control group. We report the case of a fishmonger who presented with a 1-year history of rhinoconjunctivitis and asthma. The patient attributed these symptoms to his occupational exposure within the fish market environment, which worsened in the cold storage warehouse. Symptoms improved during holidays. Diagnosis involved skin-prick tests, sIgE (ImmunoCAP-specific IgE) measurements, and bronchial challenge tests, confirming occupational asthma from fish bioaerosol exposure. Parvalbumins, common fish proteins, share structural similarities, leading to cross-reactivity in fish allergy sufferers. In this case, sensitivity to rGad c1 (cod parvalbumin) was identified as the primary trigger for the patient's asthma, and responsible for sensitizations observed across various tested fish species.

Fatal Occupational Asthma in Cannabis Production - Massachusetts, 2022

Multiple respiratory hazards have been identified in the cannabis cultivation and production industry, in which occupational asthma and work-related exacerbation of preexisting asthma have been reported. An employee working in a Massachusetts cannabis cultivation and processing facility experienced progressively worsening work-associated respiratory symptoms, which culminated in a fatal asthma attack in January 2022. This report represents findings of an Occupational Safety and Health Administration inspection, which included a worksite exposure assessment, coworker and next-of-kin interviews, medical record reviews, and collaboration with the Massachusetts Department of Public Health. Respiratory tract or skin symptoms were reported by four of 10 coworkers with similar job duties. Prevention is best achieved through a multifaceted approach, including controlling asthmagen exposures, such as cannabis dust, providing worker training, and conducting medical monitoring for occupational allergy. Evaluation of workers with new-onset or worsening asthma is essential, along with prompt diagnosis and medical management, which might include cessation of work and workers' compensation when relation to work exposures is identified. It is important to recognize that work in cannabis production is potentially causative.

Disposition of Work-Related Asthma in a Spanish Asthma Cohort: Comparison of Asthma Severity Between Employed and Retired Workers

BACKGROUND

Exposure to certain agents in the workplace can trigger occupational asthma or work-exacerbated asthma, both of which come under the heading of work-related asthma (WRA). Understanding the burden that WRA represents can help in the management of these patients.

OBJECTIVE

To assess the influence of occupation on asthma in real life and analyze the characteristics of patients with WRA included in an asthma cohort.

METHODS

This was a prospective multicenter study of a cohort of consecutive patients with asthma. A standardized clinical history was completed. Patients were classified as having WRA or non-WRA. All patients underwent respiratory function tests, FeNO test, and methacholine challenge (methacholine concentration that causes a 20% drop in FEV1) at the beginning of the study. They were classified into two groups, depending on their employment status: employed (group 1) or unemployed (group 2).

RESULTS

Of the 480 patients included in the cohort, 82 (17%) received the diagnosis of WRA. Fifty-seven patients (70%) were still working. Mean age (SD) was 46 (10.69) years in group 1 and 57 (9.91) years in group 2 (P < .0001). Significant differences were observed in adherence to treatment (64.9% in group 1 vs 88% in group 2; P = .0354) and in severe asthma exacerbations (35.7% in group 1 vs 0% in group 2; P = .0172). No significant differences were observed in the rest of the variables analyzed.

CONCLUSIONS

The burden of WRA in specialized asthma units is not negligible. The absence of differences in the severity of asthma, the treatment administered, alterations in lung function, and the number of exacerbations in those working versus not working may support the idea that advice regarding changing jobs should be customized for individual patients.

Screening tools for work-related asthma and their diagnostic accuracy: a systematic review protocol

INTRODUCTION

Work-related asthma (WRA) refers to asthma caused by exposures at work (occupational asthma) and asthma made worse by work conditions (work-exacerbated asthma). WRA is common among working-age adults with asthma and impacts individual health, work-life and income but is often not detected by healthcare services. Earlier identification can lead to better health and employment outcomes. However, the optimal tool for screening and its effectiveness in practice is not well established. Screening tools may include whole questionnaires, questionnaire items, physiological measurements and/or immunological tests. Since the publication of the most contemporary WRA or occupational asthma-specific guidelines, further studies evaluating tools for identifying WRA have been performed. Our systematic review aims to summarise and compare the performance of screening tools for identifying WRA in both clinical and workplace settings.

METHODS AND ANALYSIS

We will conduct a systematic review of observational and experimental studies (1975-2021) using MEDLINE, EMBASE, CINAHL Plus, Web of Science, CDSR, DARE, HTA, CISDOC databases and grey literature. Two independent reviewers will screen the studies using predetermined criteria, extract data according to a schedule and assess study quality using the Quality Assessment of Diagnostic Test Accuracy 2 tool. Screening tools and test accuracy measures will be summarised. Paired forest plots and summary receiver operating characteristic curves of sensitivities and specificities will be evaluated for heterogeneity between studies, using subgroup analyses, where possible. If the studies are sufficiently homogenous, we will use a bivariate random effect model for meta-analysis. A narrative summary and interpretation will be provided if meta-analysis is not appropriate.

ETHICS AND DISSEMINATION

As this is a systematic review and does not involve primary data collection, formal ethical review is not required. We will disseminate our findings through open access peer-reviewed publication as well as through other academic and social media.

PROSPERO REGISTRATION NUMBER

CRD42021246031.

Occupational Asthma Caused by Low-Molecular-Weight Chemicals Associated With Contact Dermatitis: A Retrospective Study

BACKGROUND

Occupational asthma (OA) may have different etiologies, but it is not clear whether the etiologic agents influence the clinical presentation, especially the co-occurrence of skin lesions.

OBJECTIVE

To determine the impact of different asthmagens on the characteristics of OA, with a focus on the occurrence of prior or concomitant skin disorders.

METHODS

In a retrospective analysis of patients who visited the Occupational and Environmental Disease Clinic of a tertiary referral hospital from 2009 to 2019, we classified patients into definite, probable, or possible OA according to prespecified diagnostic guidelines. In multivariate logistic regression with sensitivity analysis, we examined the relation of high- and low-molecular-weight (HMW and LMW) agents with the clinical presentation.

RESULTS

Of 209 cases of OA, 66 were caused by HMW agents and 143 by LMW agents. Patients with OA exposed to LMW agents had higher odds of having (had) allergic contact dermatitis (odds ratio, 5.45 [1.80-23.70]; P < .01), compared with patients exposed to HMW agents. Conversely, HMW agents were associated with higher odds of rhinitis symptoms (odds ratio of LMW/HMW, 0.33 [0.17-0.63]; P < .001) and high total IgE (odds ratio of LMW/HMW, 0.35 [0.17-0.70]; P < .01). Risk factors for having coexisting contact dermatitis included construction work, hairdressing, and exposure to metals or epoxy resins.

CONCLUSIONS

Among patients with OA, exposure to specific LMW agents was associated with a high frequency of contact dermatitis. Different types of asthmagens within HMW or LMW agents appear to determine the phenotype and comorbidity of OA.

Prevalence of work-related asthma among Egyptian farmers in Great Cairo

Work related asthma (WRA) refers to asthma induced by exposure to sensitizing agents and/or irritants in the workplace leaving health and economic consequences. Early diagnosis can improve the prognosis of WRA permitting sometimes full recovery. This study aimed to assess the prevalence of WRA among Egyptian adult agriculture workers. A multi-center cross sectional study included 150 adult workers from 4 different farms, during the period from 2019 and 2021. All participants were subjected to full medical history, clinical examination, chest x-ray, skin prick test and CBC to detect absolute eosinophilic count. Spirometry with post bronchodilatation test (reversibility test) at the farm (in the day of insecticide aerosol and without aerosol) and after a week off the farm was also done. Age, median ± SD, was 37.67 ± 9.75 years, duration of farming occupation was 21.84 ± 10.18 years. Of the 150 participants, 11 had WRA. Of these, 6 had allergic occupational asthma, 3/11 had work exacerbated asthma and only 2/11 had irritant occupational asthma. Of the allergic subjects, 7.3% tested positive to mixed pollens, 4.7% to Alternaria, 2% to penicillium and 2% to the farm pollens. The onset of respiratory symptoms was 13.45 ± 6.93 months after start working in the farm. A statistical significance was observed between WRA and non-WRA individuals regarding age, duration of farming occupation and asthma symptoms during workday (P < 0.001). There was a statistical significance between WRA group and non-WRA group regarding FEV1, FEV1/FVC ratio carried out at work, during holidays and during spraying (P < 0.001). Absolute eosinophilic count, mean among WRA group was 0.55 ± 0.13 (×103cells/mm3) with significance between WRA and non-WRA (P= 0.001). Farming occupation may cause WRA, therefore, more attention should be given to minimize exposure and risk of inducing WRA.

Clinical Characteristics of Irritant-Induced Occupational Asthma

BACKGROUND

Work is a substantial contributing factor of adult-onset asthma. A subtype of occupational asthma (OA) is caused by irritant agents, but knowledge of the clinical outcomes of irritant-induced asthma (IIA) is incomplete.

OBJECTIVES

To evaluate whether the clinical picture of IIA differs from that of sensitizer-induced OA.

METHODS

This retrospective study analyzed acute and subacute IIA patients diagnosed in an occupational medicine clinic during 2004 to 2018. Sixty-nine patients fulfilled the inclusion criteria, and their characteristics were analyzed at the time of the diagnosis and 6 months later. The results were compared with those of 2 subgroups of sensitizer-induced OA: 69 high-molecular-weight (HMW) and 89 low-molecular-weight (LMW) agent-induced OA patients.

RESULTS

Six months after the diagnosis, 30% of the patients with IIA needed daily short-acting β-agonists (SABA), 68% were treated with Global Initiative for Asthma, 2020 report (GINA) step 4-5 medication, and 24% of the patients had asthma exacerbation after the first appointment. IIA depicted inferiority to LMW-induced OA in daily need for SABA (odds ratio [OR]: 3.80, 95% confidence interval [CI]: 1.38-10.46), treatment with GINA step 4-5 medication (OR: 2.22, 95% CI: 1.08-4.57), and exacerbation (OR: 3.85, 95% CI: 1.35-11.04). IIA showed poorer results than HMW-induced OA in the latter 2 of these features (OR: 2.49, 95% CI: 1.07-5.79 and OR: 6.29, 95% CI: 1.53-25.83, respectively).

CONCLUSIONS

Six months after the OA diagnosis, a significant proportion of the patients with IIA remain symptomatic and the majority of these patients use asthma medications extensively suggesting uncontrolled asthma. The short-term outcomes of IIA appear poorer than that of sensitizer-induced OA.