Transcript simple pneumoconiosis PMF

ALOK SINHA
Department of Medicine
Manipal College of Medical Sciences
Pokhara, Nepal
Occupational lung disease (Pneumoconiosis)
permanent alteration of lung structure caused
by inhalation of a mineral dust and the reaction
of the lung tissue to this dust
Substances known to cause lung disease
• coal dust
• Silica
• Asbestos
• Berillium
Mineral Disease
dust
Coal
dust
I.
II.
III.
Silica
I.
Asbestos I.
II.
Examples of exposure
Simple
pneumoconiosis
Progressive
massive Fibrosis
Caplan's
syndrome
Coal mining, especially hard coal
Silicosis
Foundry work, sandblasting, stone
cutting,hard rock mining
Mining, milling, and fabrication.
Installation and removal of
insulation
Asbestosis
Benign asbestosrelated pleural
disease
Mesothelioma
Lung cancer
III.
IV.
Acute berylliosis
Beryllim I.
II.
Beryllium
granulomatosis
Mining, fabrication of electrical and
electronic equipment, workers in nuclear
and aerospace industry.
Iron oxide
Siderosis
Welding
Barium
sulphate
Baritosis
Mining
Tin oxide
Stannosis
Mining
Aluminium Like silicosis
(bauxite worker's
lung, Shaver's
disease)
Mining, firework, painting, and
armament manufacture
Pneumoconioses
non-neoplastic pulmonary diseases caused
by the reaction of the lung to the inhalation of
mainly mineral
Inhaled particles of dust size < 5 µm reach
the terminal airways and alveoli and settle on
the epithelial lining
slowly cleared by macrophages or alveolar
cells. They may pass into the
•
•
•
lymphatic system
be cleared via the airway
or remain in the alveolus
 lead to an inflammatory reaction within the
lung, depending on their physical and
chemical properties
 causes characteristic alterations in
pulmonary structure and radiological
abnormalities
 barium, tin, and iron – no fibrosis
 silica - nodular fibrosis
 asbestos - diffuse fibrosis
 coal dust - Macule formation with focal
emphysema
 beryllium- systemic response and induce
a granulomatous reaction in the lungs
Pneumoconioses can appear and progress
after the exposure has ceased
Coal-workers' pneumoconiosis
Open cast mines
deposition of coal dust within the lung and
its associated inflammatory reaction
Coal workers pneumoconiosis is of two
types Simple
pneumoconiosis
which can progress to
 Complicated
pneumoconiosis - also known
as progressive massive fibrosis (PMF)
– Related to degree of exposure to coal dust
Healthy lung
progressive massive fibrosis
Simple pneumoconiosis
Coal dust inhaled into the alveolus &
engulfed by macrophages
form a black stellate lesion - the coal
macule
coal macule
Dilated terminal
bronchiole with
Peribronchiolar
Coal ladened
macrophages
coal macules are found throughout the
lung, especially in the upper zones of the
upper and lower lobes
associated with surrounding bronchiolar
dilatation
leading to focal emphysema
cytokine release and subsequent
inflammatory cell recruitment, leading to
fibroblast activation

Progression of the disease
P.M.F.


PMF occurs on this background
with aggregation of the fibrotic
nodules to form larger lesions – 2
to10 cm diameter

central area of nodules- necrotic

outer rim - firm and collagenous



distort the adjacent lung and cause
emphysma
lesions continue to progress out of
the work environment
Larger lesions may have
• cavitation and necrosis
• areas of calcification
Clinical features
Simple pneumoconiosis
 asymptomatic with no associated
clinical signs
Progressive massive fibrosis
 Cough with mucoid or blackened
sputum
 breathlessness on exertion
 may lead to the development of
cor pulmonale
CXR
In simple pneumoconiosis
nodular shadowing of varying sizeup to 10 mm in the upper and middle
zones

graded according to the number of different
sized nodules
p = < 1.5 mm
q = 1.5-3 mm
r = 3-10 mm
PMF


diagnosed when one or more opacities of
> 1 cm diameter are present, on the
background of simple pneumoconiosis
located in the upper lobes and enlarge,
becoming increasingly radio dense and
clearly demarcated
simple pneumoconiosis
PMF
PFTs
 Simple pneumoconiosis:
•FEV1 and FVC are normal
• TLCO may be slightly decreased
PMF:
 Mixed feature
•airway obstruction due to
emphysema
•restriction due to loss of lung
volumes
Management
Minimization of dust exposure with
• improved mine ventilation
• respirator provision
• monitoring of dust levels
 Periodic CXR every 4 years
 moved to less dusty work if they show
signs of pneumoconiosis, to prevent
development of PMF
 Miners with signs of coal workers'
pneumoconiosis are entitled to industrial
injury benefits

Caplan's syndrome





Miners with seropositive rheumatoid
arthritis can develop large well-defined
nodules
occur on a background of simple pneumo
coniosis and with a relatively low coal dust
exposure
multiple and may cavitate
Cause no significant functional
impairment and have no malignant
potential
Has to be considered in the D/D of T.B.
malignency etc
chronic nodular densely fibrosing
pneumoconiosis, caused by the prolonged
inhalation of silica particles.
Long lag time of decades between exposure
and clinical disease
Insidious onset & progressive
Larger radiological opacities than those seen in
coal-workers' pneumoconiosis, and more rapid
progression
The pattern of disease depends on the level
and duration of the silicone dust exposure
quartz
Silica is present as crystalline quartz
mined and quarried
used in industries
ceramics, brick-making, and stone
masonry
Pathology
 Dust particles in the alveoli are phagocytosed
by macrophages
 removed to the lymphatics
 cause diffuse inflammatory change
 Layers of collagen are deposited around the
dust particle. Nodules are found within the
secondary pulmonary lobule
types of silicosis
Acute silicosis
Subacute silicosis & chronic silicosis
Silicotuberculosis
Acute silicosis
intense exposure to fine dusts produced
by sand blasting
apparent in workers within a few months
to a year of starting work
Rapid deterioration over 1- 2 years, with
treatment being ineffective.
Clinically
• dry cough
• shortness of breath
• feeling of tightness on breathing deeply
Rapid deterioration over a few weeks
• Fine crepitations over the lower zones
bilaterally
• Leads to respiratory failure
•
CXR Patchy bilateral lower air space
consolidation, which may look like pulmonary
oedema
Subacute silicosis
Dry cough
gradual onset of s o b
Chronic silicosis
occurs with lower dust concentrations
 PFTs- Slow decline
 mild restrictive pattern
 obstructive or
 mixed picture
(Due to emphysema)
Silicotuberculosis
 Increased likelihood of active TB infection in
people with silicosis, most likely due to the
reactivation of quiescent lesions.
 tuberculosis is three times greater than that of
age-matched controls. Those with acute and
accelerated silicosis have the highest incidence
of mycobacterial disease.
 individuals with silicosis or long-term exposure
to crystalline silica should receive a tuberculin
skin test. If the reaction is 10 mm or greater
tuberculosis chemoprophylaxis should be
administered even in absence of evidence of
active tuberculosis
 T.B. suspected when
 Cavitation
 Haemoptysis
 fever
 new soft CXR opacities
CXR
 A few upper and mid-zone nodules
occur, which become calcified after 10
years or so. no associated parenchymal
distortion
 may be associated hilar lymphadenopathy
with egg shell calcification
 disease may progress on further silica
exposure with coalescence of nodules
widespread nodules measuring 2-5 mm in diameter, with a
predominance in the middle and upper lung zones.
Management
Prevention
 by
monitoring and minimizing dust levels
with adequate ventilation
 Masks
 Stop
useful for short-term use
smoking
I. Acute berylliosis
II. Beryllium granulomatosis
(Subacute and chronic berylliosis)
Acute Berylliosis
Acute alveolitis due to the direct effects
of high-dose inhaled beryllium fumes
• widespread airway and pulmonary
oedema causes
• Dyspnoea
• Cyanosis
• widespread inspiratory crepitations
• CXR shows pulmonary oedema
• self-limiting if mild
• severe is usually fatal
• Corticosteroids may prevent
progression, but the patient is often
left with residual pulmonary
impairment
Subacute and chronic berylliosis

hypersensitivity-type disease that
occurs long time after beryllium exposure
in a minority of individuals
clinically indistinguishable from sarcoidosis
 seen in

•wives of beryllium workers
•who live near beryllium refineries
• cell-mediated immune response, with
production of numerous inflammatory
cytokines
granulomatous inflammation.
• Following a long latent period up to 10
years + after exposure, non-caseating
granulomatous tissue reactions occur in
• lungs or
• on the skin Similar to

granuloma – ball-like collection of immune
cells which forms when the immune system
attempts to wall off substances that it perceives
as foreign but is unable to eliminate

granuloma is a special type of inflammatory
reaction that can occur in a wide variety of
diseases, both infectious and non-infectious

Such substances include
– infectious organisms bacteria & fungi as well as
– other materials such as mineral dust keratin suture
fragments and vegetable particles
Clinical features
Symptoms
 Cough
 dyspnoea
 Macular
skin lesions, which do not resolve
Signs
 clubbing
& crepitations with established
fibrosis
 Hepato/splenomegaly and macular skin
lesions
Skin lesions in berryliosis
Skin lesions in berryliosis
CXR
 Fine
reticulonodular appearance
throughout both lungs. Finer nodules than
sarcoidosis.
 Progression
to irregular interstitial fibrosis,
with irregular linear opacities seen in the
lung bases.
 Hilar
lymphadenopathy can occur, but
always in association with interstitial lung
disease
BAL- High levels of T-lymphocytes
PFTs Restrictive defect, with decreased
KCO
No single test to distinguish
berylliosis from sarcoidosis
Management
Corticosteroids prevent disease
progression. Continue indefinitely as few
patients gain complete resolution of
symptoms
Annual screening of beryllium-exposed
workers with CXR
breathlessness or skin rashes- an
indication to start oral steroids to delay
progression to interstitial fibrosis
Prognosis
with very low exposure who develop CXR
changes may resolve
Granulomata do not spontaneously resolve
can be excised if causing problems, such as
troublesome lesions on the skin
 Interstitial fibrosis occurs in the lungsprogressive and leads to cyanosis and death.
complications include
 Pneumothorax
 Hypercalcaemia & hypercalciuria
 Nephrocalcinosis