A 5-year-old woman presents with dry cough and progressive breathlessness of two years duration. Examination reveals clubbing, cyanosis and bibasilar crepts. What is the probable diagnosis -

Interstitial lung diseases like pulmonary fibrosis are characterised by the the presence of exeional dyspnea,a nonproductive cough,and bi-basilar inspiratory crackles with or without digital clubbing.Cyanosis can be present due to respiratory compromise. Ref:Harrison's med:18th edition,page no:2165.