Transcript No Slide Title

Extrinsic allergic alveolitis
(hypersensitivity pneumonitis, EAA)
• Immunologically mediated inflammatory
reaction in the alveoli and in the respiratory
bronchioles
• causes: organic dusts (<5µm)
moulds
foreign proteins
some chemicals
diisocyanates
organic acid anhydrides
• often heavy, repeated exposure, most often at
the work place
hkes03
EAA
• Pathology:
Granulomatotic inflammation around the alveoli
and the peripheral bronchioles.
Exudate with plasma cells and lymphocytes.
Macrophages, epitheloid cells and giant cells in the
granulomas in the middle of the inflammation
process.
• After the exposure ceases the reaction
disappeares in 3-4 months.
• If the exposure continues, the exudation organises
into fibrine and an irreversible pulmonary fibrosis
follows.
Examples of EAA
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Farmer's lung
Saw mill worker's lung
Bird fancier's lung
Mushroom worker´s lung
Malt worker´s lung
Humidifier lung
Etiology
• Cheese washer's lung
• Suberosis
mouldy hay
mouldy wood dust
proteins in bird droppings
spores, moulds
mouldy malt
contaminated humidifier
water
Penicillium casei
cork dust mould
• Diisocyanate lung
• Hard metal worker's lung
polyurethane hardeners
hard metal dust, cobalt
Allergic alveoltis in Finland 19812001
(Finnnish Register of Occupational Diseases)
350
300
250
200
together
others
farmers
150
100
50
0
1981
1983
1985
1987
1989
1991
1993
1994
1995
1996
1997
1998
1999
2000
2001
SRR (standardized risk ratio) of EAA in some
occupations
Occupation
SRR
n
farmers and cattle tenders
9.2 (8.4-10)
928
other printing workers
5.2 (2.2-13)
5
bookbindery workers
4.4 (1.7-5)
7
printers
4.1 (2.2-7.7)
10
wood workers
2.9 (1.3-4.6)
13
typesetters
2.4 (1.3-4.6)
10
Keskinen et al. Työperäiset hengtystieallergiat. Jauhoastmasta sementtiihottumaan.Työterveyslaitos, Helsinki 1997
EAA, symptoms
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flu-like illness
cough
high fever, chills
dyspnea, chest tightness
malaise, myalgia
4-8 hours after exposure
• chronic disease: dyspnea in strain, sputum
production, fatigue, anorexia, weight loss
EAA, clinical findings
• Status
• Chest X-ray
HRCT
• lung function
• lab. tests
• BAL
dyspnea, cyanosis,
crepitant rales
digital glubbing (chronic form)
normal or small nodules/diffuse infiltrates/
ground glass appearance
chronic form: pulmonary fibrosis
normal or ground glass appearance
centrilobular micronodules
restriction, diffusing capacity decreases,
hypoxemia, obstruction, hyperreactivity
rise of sedimentation rate,
leukocytosis, neutrophilia
marked lymphocytosis,
T helper / T supressor cells decreased
EAA: HRCT, acute disease
EAA: HRCT, chronic disease
Diagnostics of EAA
• Main criteria
1. Exposure to arganic dust (history, spesific IgG antibodies, work
place measurements).
2. Typical symptoms
3. Chest X-ray findings
• Additional criteria
1. Decreased diffusion capacity
3. Hypoxia during rest or decreasing during excercise
4. Restriction in spirometric values
5. Lung biopsy with findings of allergic alveolitis
6. Provocation test (at work place) positive
All main criteria and two of the additional ones are needed for
diagnosis.
(Terho, Keuhkosairaudet, Duodecim 20
EAA, differential diagnostics
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Organic Dust Toxic Syndrome (ODTS)
Sarcoidosis
Drug-induced pneumonitis
Viral and mycoplasma pneumonias
Tuberculosis
Allergic bronchopulmonary aspergillosis
Collagen-vascular diseases
Lymphangitis carcinomatosa
Pulmonary fibrosis (DIP)
Pneumoconioses
EAA, treatment
• Stopping of exposure
• Oral steroids
• Farmer's lung: after recovery back to work
excluding/minimizing the exposure
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motorized respiratory ventilator, training!
after reorganization of the job description
follow-up
EAA, prognosis
• Continuing exposure, relapsing disease leads
to pulmonary fibrosis, permanent loss of
pulmonary function and cor pulmonale.
• When Finnish cases with farmer's lung were
followed for 10 years, 23% had findings of
pulmonary emphysema or pulmonary
fibrosis.
EAA, prevention
• reduction of dust exposure
• work hygienic improvements
• adequate respirators always during exposure
- before any symptoms!
• occupational health care
– information
– follow-up
– finding symptomatic workers in time, to prevent
permanent loss of pulmonary function
Organic Dust Toxic Syndrome (ODTS)
• opening of silos
• exposure to grain
• 1986 diPico
pulmonary mycotoxicosis
grain fever
ODTS
• Etiology:
heavy exposure to biological organic dusts
mycotoxins and endotoxins
• No sensitization
• No latency time
• prevalence numbers
farmers
mushroom cultivation
14%
37%
ODTS
• Symptoms:
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fever, main symptom
cough
irratative symptoms of mucous membranes
fatigue
myalgia
• Symptoms mild to severe, ceasing when no
exposure
• Symptoms milder than in allergic alveolitis
• No chronic form?
ODTS, diagnostics
• Criteria not yet clear
• Investigated as allergic alveolitis
• Exposure and timing of symptoms important,
often a few hours after exposure.
• No findings in chest X-ray
• lung function: normal or as in EAA but mild
• BAL: neutrophilia?
• Work place provocation test following
symptoms, temperature, diffusion capacity
and FEV1/PEF
Differential Diagnostics: Extrinsic allergic alveolitis
(EAA)/Asthma(OA)/ODTS
Feature
EAA
OA
ODTS
Symptoms
Cough, dyspnea
fever
Cough, dyspnea
Flu-like symptoms
fever
Onset after exposure
Gradual after 4-8h Immediate or
late
Physical findings
Bibasil. crackles
Expirat. wheezes None
Chest X-ray
Infiltrates/norm.
Normal
Normal
Lung function
Restrictive
Obstructive
Normal?
Peripheral eosinophilia
No
Yes?
No
Gradual after 3-8h
Conclusion
• Farmer´s lung is the most usual extrinsic
allergic alveolitis. Chronic form leads to
severe disability.
• Reduction of the exposure to biological dust
by work hygienic improvements and using
adequate respirators is important. The
humidifiers and other sources of exposure
should be cleaned.
• Early recognition of the symptoms is
essential.
• ODTS is a milder syndrome, symptoms can
be prevented using respirator when exposed.
Literature
• Pickering CAC, Newman Taylor AJ. Extrinsic allergic
bronchioloalveolitis (hypersensitivity pneumonia). In RW Parkes,
Occupational Lung Disorders, Third edition1994, Butterworth Heineman
Ltd, UK,
• Terho EO. Orgaanisten pölyjen aihettamat keuhkokudoksen
yliherkkyysreaktiot. Kirjassa Allergologia, toim. Haahtela T, Hannuksela
M, Terho E.O. Kustannusosakeyhtiö Duodecim, 1999:391-403.
• Terho EO. Allerginen alveoliitti ja sitä muistuttavat sairaudet. Kirjassa
Keuhkosairaudet, toim. Kinnula V. Laitinen L.A.L, Tukiainen P.
Kustannusosakeyhtiö Duodecim, 2000:336-342.