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Detailed information of BRONCHIOLITIS OBLITERANS
BRONCHIOLITIS OBLITERANS
DEFINITION:
An acquired disease of the bronchioles characterized by recurrent
wheezing and eventually airway obstruction.
EPIDEMIOLOGY:
- incidence: ?
- age of onset:
- risk factors:
PATHOGENESIS:
- first described by Lange in 1901
- through a number of precipitating factors, the epithelial
cells of the bronchioles and smaller airways are injured and the
regenerative response results in the production of a large amount
of granulation tissue and necrosis -> nodular masses of
granulation and fibrosis -> airway obstruction
- precipitating factors:
- infection - adenovirus bronchiolitis and pneumonia
- measles, influenzae, mycoplasma, pertussis
- not RSV bronchiolitis
- drugs - penicillamine
- inhalants - HCl, nitric oxide, sulfur dioxide
- barotrauma - Bronchopulmonary Dysplasia
- aspiration - Gastroesophageal Reflux
- connective tissue diseases - SLE
- post transplantation - heart-lung, bone marrow (component of
graft vs host disease)
PATHOLOGY:
- destruction of the mucosa and lumen filled with fibrous
tissue
- terminal bronchioles are occluded and distal bronchioles are
dilated
2. Alveoli
- overdistention, atelectasis, fibrosis
DIAGNOSIS:
- development of chronic bronchiolitis/asthma with progressive
airway obstruction after a respiratory insult (i.e., adenovirus
bronchiolitis or pneumonia)
2. Laboratory
- radiologic and pathologic findings
CLINICAL FEATURES:
- similar to acute RSV bronchiolitis except rhinorrhea is not
a prominent feature but may be complicated by bronchopneumonia -
cough & fever -> wheezing & dyspnea -> respiratory distress
+/-cyanotic spells
- pattern may resemble bronchitis, bronchiolitis, or pneumonia
2. Course
- clinical features wax and wane for several weeks to months
- recurrent episodes of wheezing, dyspnea, productive and
chronic cough, pneumonia & atelectasis (a chronic form of
bronchiolitis)
- fixed airway obstruction
3. Long-term Course
- acute - some deteriorate rapidly and die
- chronic
- of those with adenovirus (types 7 & 21) bronchiolitis or
pneumonia, 60% will develop chronic pulmonary disease:
- persistent RUL (young children) and LLL (older children)
atelectasis
- bronchiectasis
- recurrent pneumonias
- unilateral hyperlucent lung syndrome (Swyer-James
Syndrome)
INVESTIGATIONS:
- pattern similar to miliary TB
- may show nonspecific diffuse infiltrates
- peribronchial thickening
- increased interstitial markings
- areas of patchy bronchopneumonia
- collapse and consolidation of segments or lobes
2. Long-Term
- increased pulmonary markings
- generalized hyperinflation
- unilateral hyperlucent lung syndrome
2. Bronchogram
- bronchiolar obstruction with little or no contrast
reaching the lung periphery (pruning of bronchial tree)
3. Pulmonary Angiogram
- decreased vasculature to involved areas
2. Biopsy
- diagnostic - see Pathology
MANAGEMENT:
- steroids may be of benefit otherwise supportive care only
- poorly responsive to bronchodilators
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Pediatric Database - BRONCHIOLITIS OBLITERANS
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