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Fibrosing Interstitial Lung Disease H010

Last amended 
2 September 2021
Current RMA Instruments
Reasonable Hypothesis SOP
85 of 2021
Balance of Probabilities SOP
86 of 2021
Changes from previous Instruments

SOP Bulletin 224

ICD Coding
  • ICD-9-CM Codes: 500, 502.1, 502.2, 503, 506.4, 508.1, 508.8, 515, 516.3
  • ICD-10-AM Codes: J60, J62.8, J64, J68.4, J70.1, J70.8, J84.1
Brief description

This SOP covers idiopathic fibrosing alveolitis and a range of other lung diseases that feature chronic inflammation and fibrosis.  This SOP does not cover fibrosis associated with systemic disease and has a number of other exclusions.  Asbestosis is a form of fibrosing interstitial lung disease, but there is a separate SOP for asbestosis that should be applied if that diagnosis is confirmed (see comments below).  Note carefully the included and excluded conditions, detailed below, before applying this SOP.  The terminology can be confusing – seek medical advice if in doubt.

Confirming the diagnosis

This diagnosis is complex and should be made by a specialist respiratory physician.  High resolution CT / MRI scanning or lung biopsy is usually required.

Additional diagnoses covered by SOP
  • Acute interstitial pneumonia
  • Berylliosis
  • Coal worker’s pneumoconiosis
  • Diffuse (interstitial) pulmonary fibrosis
  • Drug-induced interstitial pneumonitis
  • Fibrosing alveolitis (idiopathic or cryptogenic)
  • Hamman-Rich syndrome
  • Idiopathic pulmonary fibrosis
  • Lymphoid interstitial pneumonia
  • Non-specific interstitial pneumonia
  • Radiation fibrosis
  • Silicosis (chronic)
Conditions that may be covered by SOP
  • Usual interstitial pneumonia
Conditions not covered by SOP
  • Asthma*
  • Bronchiectasis*
  • Bronchiolitis obliterans organising pneumonia* / cryptogenic organising pneumonia
  • Chronic bronchitis* - chronic obstructive pulmonary disease SOP
  • Chronic obstructive pulmonary disease*
  • Desquamative interstitial pneumonia#
  • Eosinophilic pneumonia#
  • Emphysema* - chronic obstructive pulmonary disease SOP
  • Extrinsic allergic alveolitis* (hypersensitivity pneumonitis SOP)
  • Histiocytosis (X)#
  • Hypersensitivity pneumonitis*
  • Other organising pneumonia# (excl BOOP)
  • Pleural plaque*
  • Pulmonary alveolar proteinosis#
  • Pulmonary Langerhan’s cell histiocytosis#
  • Pulmonary manifestations of systemic diseases:
    • Sarcoidosis*
    • Amyloidosis*
    • Rheumatoid arthritis*
    • Systemic lupus erythematosus*,
    • Scleroderma / Systemic sclerosis*
    • Polymyositis#
    • Sjögren’s disease#
  • Respiratory bronchiolitis associated interstitial lung disease#

* another SOP applies

# non-SOP condition


Asbestosis can present with a similar clinical picture to other forms of fibrosing interstitial lung disease and with very similar findings on radiology.  If the diagnosis of asbestosis is established by the demonstration of a diagnostic number of asbestos bodies in the lung on histology or cytology, or based on a convincing history of heavy inhalational asbestos exposure, then the asbestosis SOP applies.  If fibrosing interstitial lung disease is present, but a diagnosis of asbestosis cannot be confirmed, then the fibrosing interstitial lung disease SOP applies.  The fibrosing interstitial lung disease SOP has factors for asbestos exposure, so effectively, asbestos-related fibrosing interstitial lung disease is covered by both SOPs.

Clinical onset

The condition usually presents with gradual onset of shortness of breath on exertion (dyspnoea) and a non-productive cough, generally in someone of middle age or older.  The condition may also be found incidentally on imaging.  Pinpointing clinical onset based on dyspnoea may be difficult and imprecise.

Clinical worsening

The usual course for the condition is a gradual decline in lung function and worsening symptoms.  Evidence of progression or acceleration beyond the usual course would be required for clinical worsening to apply.