• DIAGNOSIS• MONITORING

ASSESSMENT OF OCCUPATIONAL

ASTHMA

History of exposure to sensitizing agentsAbsence of asthma symptoms before

beginning employmentDocumented relationship between symptoms

and workplace (improving symptom when away from work & worsening symptoms upon return to work

HISTORY

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WHAT SYMPTOMS SHOULD YOU LOOK OUT FOR?

The symptoms start as · runny eyes and nose

· itchy eyes and nose

and may develop into the more serious problems of asthma

· breathlessness

· wheezing

· tightness of chest

· coughing

DIAGNOSING OCCUPATIONAL ASTHMA

HistoryInvestigation

Detailed history of past & present occupational exposures

Cough – at work/ end of shift, precedes wheezing

Concurrent – rhinorrhoea, nasal congestion,

lacrimation, conjunctivitis

Symptoms improve – at weekends & holidays, persist – advanced stage.

Diagram – SpirometryParametersProcedureDiagnosis

SPIROMETRY

FEV1 (Forced expiratory volume in 1 second)Forced Vital Capacity (FVC)FEV1/FVC ratio

PARAMETERS

Marked reduced in FEV1Reduced in FVCThe FEV1/ FVC ratio is reducedSignificant improvement of the FEV

1 (>12%) following administration of a bronchodilator

Diurnal variability

DIAGNOSIS

Measure expirationEasySteps

PEAK EXPIRATORY FLOW METER

STEPS TO USE PEAK EXPIRATORY FLOW METER

1. Stand up or sit up straight.2. Make sure the indicator is at the bottom of the

meter (zero).3. Take a deep breath in, fi lling the lungs completely.4. Place the mouthpiece in your mouth; lightly bite

with your teeth and close your lips on it. Be sure your tongue is away from the mouthpiece.

5. Blast the air out as hard and as fast as possible in a single blow.

6. Remove the meter from your mouth.7. Record the number that appears on the meter and

then repeat steps one through seven two times.8. Record the highest of the three readings in an

asthma diary. This reading is your peak expiratory flow (PEF).

Similar with asthmaDiffers according to the severity :

1. PEF > 75% of predicted or best value (MILD)

2. PEF between 50% – 75% of predicted or best value (MODERATE)

3. PEF < 50% of predicted or best value (SEVERE)

4. PEF < 30% of predicted or best value Reversibility testing

DIAGNOSIS

Pharmacological therapy for OA is identical to therapy for other forms of asthma, but it is not substitute for adequate avoidance

PHARMACOLOGICAL THERAPY

(Bateman, et al, 2008)

PHARMACOLOGICAL THERAPY Treatment

Controllers Relievers

1) Inhaled glucocorticosteroids 1) Rapid-acting inhaled b2-agonists

2) Leukotriene modifiers 2) Anticholinergics

3) Long-acting inhaled b2-agonists 3) Short-acting oral b2-agonists

4) Theophylline

5) Anti-IgE

6) Others Systemic glucocorticosteroidsOral anti-allergic compounds

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OCCUPATIONAL ASTHMA CHECKLIST

Reminder, if you have trouble with wheezing, coughing or shortness of breath at work, you could have occupational asthma:

· Consult your physician. He or she may suggest a lung function test.

· See your work supervisor for details about potential hazards in your work environment.

· Have the tests and evaluation required to prove the suspected occupational asthma and its cause.

· Seek your physician's advice about therapy for occupational asthma.

Pre employment stage: asked about pre existing asthma (not suitable for this work)

Lung function test and referral for immunological blood test or skin prick test may be appropriate

Frequent health surveillance indicated First few years of exposure (OA risk greatest during early

years) Workers with pre existing asthma Workers who develop rhinitis & workplace exposure should

be investigated and reduced

HEALTH SURVEILLANCE