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| '''For patient information click [[{{PAGENAME}} (patient information)|here]]''' | | __NOTOC__'''For patient information click [[{{PAGENAME}} (patient information)|here]]''' |
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| {{Occupational asthma}} | | {{Occupational asthma}} |
| {{CMG}}; {{AOEIC}} {{LG}} | | {{CMG}}; {{AOEIC}} {{LG}} |
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| ==[[Occupational asthma overview|Overview]]== | | ==[[Occupational asthma overview|Overview]]== |
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| ==[[Occupational asthma screening|Screening]]== | | ==[[Occupational asthma screening|Screening]]== |
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| ==[[Occupational asthma natural history, complications and prognosis|Natural History, Complications and Prognosis]]== | | ==[[Occupational asthma natural history, complications and prognosis|Natural History, Complications, and Prognosis]]== |
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| ==Diagnosis== | | ==Diagnosis== |
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| [[Occupational asthma diagnostic criteria|Diagnostic Criteria]] | [[Occupational asthma history and symptoms|History and Symptoms]] | [[Occupational asthma physical examination|Physical Examination]] | [[Occupational asthma laboratory findings|Laboratory Findings]] | [[Occupational asthma electrocardiogram|EKG]] | [[Occupational asthma chest x ray|Chest X ray]] | [[Occupational asthma other diagnostic studies|Other Diagnostic Studies]]
| | [[Occupational asthma history and symptoms|History and Symptoms]] | [[Occupational asthma physical examination|Physical Examination]] | [[Occupational asthma laboratory findings|Laboratory Findings]] | [[Occupational asthma electrocardiogram|EKG]] | [[Occupational asthma chest x ray|Chest X ray]] | [[Occupational asthma other diagnostic studies|Other Diagnostic Studies]] |
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| ==Treatment== | | ==Treatment== |
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| ==Case Studies== | | ==Case Studies== |
| [[Occupational asthma case study one|Case #1]] | | [[Occupational asthma case study one|Case #1]] |
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| ==Diagnosis==
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| ===Non-specific bronchial hyperreactivity===
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| * A non-specific bronchial hyperreactivity test involves testing with methacoline, after which the Forced Expiratory Volume in 1 second (FEV<sup>1</sup>) of the patient is measured.
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| * This test is often used for measuring the intensity of a person's asthma and to confirm that the person needs to be treated for asthma. Other non specific tests could even require the patient to run in open air or on a treadmill for a few minutes at a continuous pace. In this case, the individual’s Peak Expiratory Flow Rate (PEFR) is measured. (The peak expiratory flow rate measures how fast a person can exhale) <ref>[http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Retrieve&db=PubMed&dopt=Abstract&list_uids=9408523 Risk and incidence of asthma attributable to occupational exposure among HMO members.] Milton DK, Solomon GM, Rosiello RA, Herrick RF. Am J Ind Med 1998;33:1–10.</ref>.
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| ===Skin prick tests===
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| * A skin prick test is performed on the inner aspect of the forearm. A technician will draw a grid and systematically drop specific allergens within grid spaces. The skin is then pricked through a lancet to induce a potential interaction.
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| * Reactions, if any, occur within 10-15 minutes of allergen contact. The results of these reactions assist in determination of level of severity of allergic reaction and types of allergic triggers.<ref>http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9333767 Kroczyńska-Bednarek J, Grzelewska-Rzymowska I, Tymińska K.</ref>
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| ===IgE-specific tests===
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| * Immunoglobulin E is an antibody that is effective against toxins. Since it can also trigger allergic reactions to specific [[allergens]] like [[pollen]], the IgE test is performed to evaluate whether the subject is allergic to these substances<ref>[http://www.allergysa.org/appen9.htm Allergy Society of South Africa.] The Skin Prick Test. Toerien A,Potter P C, Buys C</ref>.
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| ===Spirometric tests===
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| * Conventionally, a [[spirometer]] is a device used to measure timed expired and inspired volumes.
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| * Expired and inspired volume measurements then enable us to measure how quickly the lungs can be emptied and filled and whether it is effective.
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| * These measurements need to be stated at body temperature and the pressure will have to be saturated with water vapor to get the correct values. The specificity of measurement is important as if the spirometer is dry, the recorded volume of air displaced is lower than that actually displaced by the lungs<ref>http://researchnews.osu.edu/archive/hayfcare.htm</ref>.
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| ===Peak Expiratory Flow at work===
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| * This test uses the peak expiratory flow at rest (PEFR) method. The primary difference from the at-rest test is that at work testing measures the functioning of the patient's airways at his place of work and not necessarily in a controlled environment. The patient breathes into a Peak Expiratory Flow monitor (a hand-held device that has a mouth piece at one end and a scale with an indicator on the other).<ref>http://www.nationalasthma.org.au/html/management/spiro_book/sp_bk002.asp</ref>
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| ===[[Specific inhalation challenge]]===
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| <ul> <li><b>Realistic method</b></li>
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| “The Realistic Method” is a whole body sealed chamber where the patient is exposed to articles that are present in their workplace. This method has the advantage of being able to assess, albeit highly subjectively, ocular and nasal symptoms as well as a reduction in FEV<sup>1</sup>.
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| <li><b>Closed-circuit method</b></li>
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| This test requires the patient to breathe [[aerosols]] of the suspected ‘asthmagens’ through an oro-facial mask. These ‘asthmagens’ are aerosolized using closed circuit chambers, and the quantities and concentrations administered being minute and extremely stable minimize the risk of exaggerated responses.
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| </ul>
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| *Of the above methods of doing a diagnosis, procedures such as monitoring of [[spirometry]] or [[peak expiratory flow]] at work and Specific Inhalation Challenges (SIC) have been proved as the most objective and reliable methods.
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| ==Treatment==
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| *According to the [[Canadian Centre for Occupational Health and Safety]] (CCOHS), better education of workers, management, unions and medical professionals is the key to the prevention of OA. This will enable them to identify the risk factors and put in place preventive measures like masks or exposure limits, etc.
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| * Recovery is directly dependent on the duration and level of exposure to the causative agent. Depending on the severity of the case, the condition of the patient can improve dramatically during the first year after removal from exposure.
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| *Three basic types of procedures are used for treating the affected workers<ref name="EvidenceReport"/>:
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| ====1) Reducing exposure====
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| * This method is most effective for those affected by irritant-induced OA.
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| * Thus, by reducing their exposure duration and level to the causative agent, the probability of suffering another reaction is lowered. But exposure can be reduced in other ways like making use of face masks or providing better ventilation.
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| * Now, more and more di-isocyanate free spray paints are available.
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| * Similarly, most hospitals and healthcare companies have exchanged latex gloves for other materials. Thus, reducing exposure to known asthmagens can also be used as a preventive measure.
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| ====2) Removal from exposure====
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| * Persons affected by OA that occurred after a latency period, whether a few months or years, must be immediately removed from exposure to the causative agent. This is their only chance of recovery.
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| * This entails severe socio-economic consequences for the worker as well as the employer due to loss of job, unemployment, compensation issues, quasi-permanent medical expenditures, hiring and re-training of new personnel, etc.
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| * According to recent research, the probability that those who suffer from OA remain unemployed longer than those who suffer from non-occupational asthma is higher. One solution to this problem is relocating the employee in the same company away from the causative agents.
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| ====3) Medical and pharmacological treatment====
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| * Anyone diagnosed with asthma will have to undergo medical treatment.
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| * This is complementary to either removing or reducing the patient’s exposure to the causal agents.
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| * Two types of medication can be used:
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| <ul>
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| <li><b>Relievers or bronchodilators</b></li>
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| {{main|Bronchodilator}}
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| Short-acting [[beta-agonist]]s like [[salbutamol]] or [[terbutaline]] or long-acting beta-agonists like [[salmeterol]] and [[formoterol]] or [[anticholinergic]], etc. dilate airways which relieve the symptoms thus reducing the severity of the reaction. Some patients also use it just before work to avoid a drop in the FEV<sup>1</sup>.
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| <li><b>Preventers</b></li>
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| Anti-inflammatory agents like [[corticosteroid]]s, LKTRA or mast cell stabilizers can be used depending on the severity of the case.
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| </ul>
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| ==Compensation issues==
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| * When a person is diagnosed as having occupational asthma, it can result in serious socio-economic consequences not only for the workers but also for the employer and the healthcare system. The employee has to be taken off job immediately to prevent any further damage to his health. And, the probability of being re-employed is lower for those suffering from OA as compared to those suffering from normal asthma. The employer not only pays compensation to the employee, but will also have to spend a considerable amount of time and energy and funds for hiring and training new personnel. <ref>http://www.nlm.nih.gov/medlineplus/ency/article/003443.htm</ref><ref>[http://www.erj.ersjournals.com/cgi/content/abstract/7/5/969/ Medicolegal and compensation aspects of occupational asthma.] Dewitte JD, Chan-Yeung M, Malo J-L.</ref>
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| ==Related Chapters== | | ==Related Chapters== |
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| *[[Specific inhalation challenge]] | | *[[Specific inhalation challenge]] |
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| ==References==
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| {{reflist|2}}
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| [[Category:Disease]]
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| [[Category:Pulmonology]] | | [[Category:Pulmonology]] |
| [[Category:Asthma]]
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| [[Category:Occupational safety and health]]
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| [[Category:Up-To-Date]]
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| [[Category:Up-To-Date pulmonology]]
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| {{WikiDoc Help Menu}} | | {{WikiDoc Help Menu}} |
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