occupational asthma

1. PRESENTED BY - DR RASHI VOHRA
MODERATOR – DR JAGDISH RAWAT

3. It is asthma arising de novo that is initiated
as a consequence of an exposure to a specific
etiological agent at workplace in people
without prior asthma.

6.  SMOOTH MUSCLE DYSFUNCTION
 AIRWAY REMODELLING
 AIRWAY INFLAMMATION
THE ABOVE LEAD TO ASTHMA LIKE SYMPTOMS SUCH AS
• COUGH
• WHEEZE
• DYSPNEA
• ITCHY EYES
• TEARING
• SNEEZING
• NASAL CONGESTION
• RHINORRHEA

7. Caused by specific sensitizing agent in the work
place where the specific sensitizing agent causes
asthma through an identified underlying
immunological mechanism.
Occurs after a latency period of several weeks to
about 2 years.
Can be due to : High Molecular Weight Agents
: Low Molecular Weight Agents

8. Bacteriological or vegetable origin
Organic proteins/ polysaccharides
Produce Type I Hypersensitivity Reaction
Examples : Grains and flour ,coffee beans, latex,
enzymes (papain, trypsin etc)

9. Chemical origin
Produce Type IV hypersensitivity reaction
Examples : Isocyanates , formaldehyde,
glutaraldehyde, wood(red cedar), antibiotics, glues
etc

11. ENVIRONTMENTAL FACTORS
CIGARETTE SMOKING
LEVEL OF EXPOSURE
HOST RELATED EXPOSURE
OCCUPATIONAL RHINITIS
ATOPY
GENETIC SUSCEPTIBILITY
PRE EXPOSURE SENSITIZATION

13. It is a non immunological form of occupational
asthma that results from a single or multiple high
dose exposure to irritant products.
Develops early after exposure within minutes to
hours.

14.  SPILL OF VOLATILE SUBSTANCE
 ACCIDENTAL RELEASE OF IRRITANTS
UNDER PRESSURE
 ACCIDENTAL FIRE WITH RELEASE OF
TEHRMAL DEGRADATION PRODUCTS

16.  Sensitizer-induced
 Specific antigen
 Minimal exposure
 PPE often insufficient to
control symptoms
 Medical removal usually
necessary
Irritant-induced
 Any irritant
 Moderate to heavy exposure
 PPE often effective in
preventing episodes
 Medical removal the last
resort

17. Worsening of asthma that is already pre
existing or concurrent, triggered by non
specific irritants in a work place.
Increased frequency and worsening of
symptoms
Increase in medication at work

18.  Chemicals
 Dust
 Smoke
 Paints
 Cleaningproducts
 Exercise
 EmotionalStress

20.  Severe form of irritant induced asthma
,symptoms develop within minutes to
hours after a single accidental inhalation
of a high concentration of irritant gas,
aerosol, vapour and smoke.

21. 1. A documented absence of previous respiratory complaints
2. Onset of symptoms occurring after a specific exposure
incident or accident.
3. Exposure to gas, smoke, fume or vapor present in high
concentration and with irritant property.
4. Onset of symptoms occurring within 24 hours of the
exposure and persisting for atleast 3 months.
5. Symptoms stimulating asthma with wheeze, cough and
dyspnoea.
6. Pulmonary function test may show airflow obstruction.
7. Methacholine challenge test positive
8. Other pulmonary disease to be ruled out.

22. Cough ( may cause disturbed sleep)
Wheeze
Breathlessness

23. Focal epithelial desquamation
Squamous cell metaplasia
Sub epithelial fibrosis
Thickening of basement membrane
Lymphocytic inflammation

24. Lung function test- reduced FEV1, increased
RV.
Airflow obstruction- partially reversible
Methacholine Challenge Test- Positive
BAL- lymphocytes

25. High dose oral corticosteroids
Conventional asthma guidelines
Progressive irreversible obstruction indicates
obliterative bronchiolitis, continue high dose
oral steroid

26.  SURVEILLANCE OF WORK-RELATED AND OCCUPATIONAL
RESPIRATORY DISEASE
 The commonest cause of occupational asthma in the UK consists
of the di-isocyanates (used in various industries such as in spray
painting).
 Other important asthma hazards include colophony fume (from
soldering flux).
 The SWORD scheme was useful in picking up trends of concern
such as a substantial increase in asthma associated with
exposure to latex, and thus helped in raising awareness and
reducing the risks of this problem.

27.  Current and previous jobs
 Symptoms within months of job change
 New agent introduced in workplace
 Specific exposure to an agent
 Onset of symptoms
 Other workers affected or left job due to this
 Temporal relationship between exposure at work and disease
exacerbations
 Asthma like symptoms during working days and improvements
during holidays
 Negative history of past respiratory diseases
 Occupational hygiene practices

28. SPIROMETERY
PEAK EXPIRATORY FLOW RATE
BRONCHIAL CHALLENGE TEST
SPECIFIC INHALATION CHALLENGE
SKIN PRICK TEST
SPUTUM EOSINOPHILS
EXHALED NO
SERUM IMMUNOLOGIC TESTING

29. FEV1 REDUCED , FEV1/FVC REDUCED
BRONCHODILATOR REVERSIBILITY
TEST
INCREASE IN FEV1 >12% AND >200 ML
FROM BASELINE

30. AGENTS USED – METHACHOLINE,HISTAMINE AND
INHALED MANNITOL
LEADS TO BRONCHOCONSTRICTION
TO CHECK AIRWAY HYPER RESPONSIVENESS
ASTHAMATICS RESPOND TO LOWER DOSES OF THE
DRUG

31. It is a diagnosis tool to assess airway responsiveness
to "sensitizing" substances as opposed to nonspecific
stimuli such as pharmacological agents (i.e.
histamine, methacholine), cold air and exercise.
FEV1 is subsequently measured using another device
and compared to a baseline .A positive response is
usually a decrease in baseline FEV1 of 15 to 20
percent.

35.  RELIEVERS
1. Beta-2 Agonist
2. Short acting
3. Long Acting
4. Theophylline
5. Anti cholinergic- long acting, short acting

36.  PREVENTORS
1. Sodium chromoglycate
2. Nidocronil sodium
3. H1 Receptor antagonist
4. Ketotifen
5. Inhaled corticosteroids
6. Systemic corticosteroids

37.  Allergen immunotherapy, also known as desensitization or hypo-
sensitization, is a medical treatment.
 Immunotherapy involves exposing people to larger amounts
of allergen in an attempt to change the immune system's response.
 Types- SCIT
- Sublingual
- Oral
- Transdermal

39. 1.Pre-placement Assessment
2.Exposure control
3.PPE & Awareness
4.MSDS
Early detection
1. Spirometry
2. Skin testing
1.Employee Accommodations
2.Job Retraining
3.Upgrading standards of care
Tertiary
prevention
Secondary
prevention
Primary
Prevention
PREVENTION AND
CONTROL