Sjögren Syndrome
Etiology Sjögren’s syndrome, or “sicca syndrome,” is a disorder of the immune system that is largely defined by its two most common symptoms—dry eyes and a dry mouth; these symptoms…
Behçet Disease
Etiology, Prevalence, and Epidemiology Behçet disease is an uncommon systemic disorder of unknown etiology characterized by vasculitis and the triad of recurrent ulcers of the oral and genital mucosa with…
Interstitial Pneumonia With Autoimmune Features
Interstitial pneumonia with autoimmune features (IPAF) refers to the clinical entity of interstitial lung disease (ILD) in patients with features of autoimmunity but without overt connective tissue disease (CTD). IPAF…
Goodpasture Syndrome (Anti–Basement Membrane Antibody Disease)
Etiology, Prevalence, and Epidemiology Goodpasture syndrome, also known as anti–basement membrane antibody disease, is an autoimmune disorder characterized by repeated episodes of pulmonary hemorrhage, usually associated with glomerulonephritis and the…
Polymyositis/Dermatomyositis
Etiology Immune-mediated muscle inflammation and vascular damage are the hallmarks of polymyositis (PM) and dermatomyositis (DM). In PM the immune system is primed to act against muscle antigens, whereas in…
Lymphangioleiomyomatosis and Tuberous Sclerosis
Etiology Lymphangioleiomyomatosis (LAM) is a systemic disease of unknown etiology, affecting almost exclusively women. LAM is characterized by idiosyncratic smooth muscle cell proliferation (LAM cells), which leads to lung cysts,…
Mixed Connective Tissue Disease
Etiology Mixed connective tissue disease (MCTD) is a disease with certain features of polymyositis, scleroderma, and systemic lupus erythematosus. Much of the evidence that MCTD is a distinct clinical entity…
Smoking-Related Interstitial Lung Disease
Currently, the worldwide number of tobacco smokers is estimated at 1.1 billion people, with the World Health Organization estimating that tobacco use is responsible for approximately 6 million premature deaths…
Bacterial Pneumonia
Etiology, Prevalence, and Epidemiology Pneumonia and influenza represent the eighth leading cause of mortality in the United States, with an estimated 1.3 million hospital admissions yearly attributable to pneumonia in…
Nonspecific Interstitial Pneumonia
Etiology, Prevalence, and Epidemiology Nonspecific interstitial pneumonia (NSIP) is a chronic interstitial lung disease characterized by homogeneous expansion of the alveolar walls by inflammation or fibrosis or both. NSIP is…
