Saturday, December 04, 2010

Quik Review: Bronchioliotis obliterans with organizing pneumonia (BOOP)

What is BOOP ?
  • BOOP is a distinct spectrum of lung disease charecterised by wide spread inflammation of small conducting  airways (unlike ARDS where the site of injury is the alveolar membrane) initiated by various injurious agents like viruses,toxic fumes and connective tissue disorders followed by an attempt to heal by forming granulation tissue predominantly in the distal bronchioles (hence bronchiolitis obliterans) which may resolve fully either spontaneously or with steorids  or may progress to irreversible fibrosis of distal airways ( hence organising pneumoniaas coined in the preantibiotic era) . Epler, Colby and Carrington coined the term BOOP.
When to suspect BOOP?
  • A middle aged male or female presenting with flu like syndrome with cough and breathlessness lasting about 1-2months with a background history of viral infection,connective tissue disorders, toxic fume inhalation and on certain drugs as methotrexate or amiodarone,whose chest x ray shows bilateral patchy densities without volume loss, think of BOOP. Most of them have crackles and wheeze on auscultaion.

What are causes of BOOP?
  • Connective tissue disorders eg Rheumatoid arthritis,SLE etc
  • Toxic fumes
  • Post infective eg Viral pneumonias
  • Idiopathic
Diagnostic features?
  • CXR: Patchy opacities which begins unilaterally and then becomes bilateral
  • CT Thorax: Ground glass opacities
  • PFT: Restrictive pattern inspite of obtructive pathology
  • Biopsy of lungs: Is the diagnostic test
How to treat?
  • Prednisolone : Starting at 1-2mg/kg tapered over 3-6weeks.
  • May need steroid sparing drugs as Azathioprine if signs and symptoms reccur with steroid tapering.