Table 2. Clinical features of respiratory bronchiolitis-interstitial lung disease (RB-ILD), desquamative interstitial pneumonia (DIP) and pulmonary Langerhans’ cell histiocytosis (PLCH) in comparison with combined pulmonary fibrosis and emphysema (CPFE)
Smoking100%90%>90%100% (heavy smokers)
Age3rd to 5th decade3rd to 5th decade3rd to 4th decade6th to 7th decade
Sex M:FSlight male dominanceNearly 2:11:1Almost all male
Presenting symptomsDyspnoea and coughDyspnoea and coughDyspnoea, cough and acute chest pain (when pneumothorax is present)Dyspnoea and cough
Systemic involvementNoPossible, rarePossibleNo
Crackles∼50%60%Usually absent87% basal
ClubbingRareNearly 50%Exceptional43%
Pulmonary functionMixed defect or normal; reduced DL,CORestrictive; reduced DL,COObstructive or restrictive; reduced DL,CO (especially in patients with vascular involvement)Sub-normal pulmonary volumes; severe reduction of DL,CO
Pulmonary hypertensionNoRarePossible47% at diagnosis; between 50% and 90%
Desaturation on 6MWTNoPossibleRareFrequent
Spontaneous improvementPossibleOccasionallyPossibleNo
TreatmentSmoking cessationSmoking cessation and steroidsSmoking cessation and steroids?Smoking cessation
Response to steroidsGoodGoodFairNone
PrognosisGoodGoodGoodPoor (5-yr survival is 55%)
Complete recovery possibleYesYesYesNo
Correlation with lung cancer or other neoplasmsNoRareFrequentFrequent (near 50%)
  • M: male; F: female; 6MWT: 6-min walk test; DL,CO: diffusing capacity of the lung for carbon monoxide.