Idiopathic Pulmonary Fibrosis (hereafter referred to as IPF for short), is a chronic and progressive disease of the lung wherein the lung tissues thicken, stiffen and scar without a definitive cause. Recent studies believe that scarring or an inflammatory response of the lung tissues begins when the tissues are repeatedly injured by some chemical or an unknown pathogen.
In IPF, the interstitium (especially the walls of the alveoli therein) of the lungs undergo abnormal and excessive collagen deposition with minimum associated inflammation (Source: "Idiopathic Pulmonary Fibrosis: Diagnosis and Treatment". American Journal of Respiratory and Critical Care Medicine 161 (2): 646–664. 1 February 2000. PMID 10673212). Thus, the homeostasis of the alveolar epithelial cells is disturbed by some external or endogenous stimuli. The factors could be anything from cigarette smoking, infections, environmental pollutants, gastro-esophageal reflux disease, drugs, or any other unknown cause. The disruption of homeostasis then causes overproduction of collagen and fibronectin. Eventually as the cause of the fibrosis continues to be present, abnormal epithelial healing sets the stage for progressive fibrosis and architectural distortion of the lung sets in.
As per the American Thoracic Society/European Respiratory Society (ATS/ERS) consensus in 2002, IPF is the most common of the seven idiopathic interstitial pneumonias classified.
Symptoms of IPF are common with many infectious lung conditions and thus, differential diagnosis approach is required at arriving at a conclusion. The symptoms are usually:
• Dry cough
• Dyspnoea (shortness of breath), labored breathing
• Easy fatigue
• Occasional chest pain
• Rasping sounds heard from the lungs while breathing, through a stethoscope
• Weight loss
• Pulmonary hypertension
• Cyanosis (bluish skin color due to deficient oxygen levels in blood)
• Clubbing of fingers
As you can see the symptoms above are common with so many other lung diseases that differential diagnosis needs to be done for the following conditions to rule them out and zero in on IPF. These diseases could be: