Interstitial lung disease evaluation: detecting connective tissue disease

Interstitial lung disease (ILD) is a common manifestation of connective tissue disease (CTD) and is often associated with significant morbidity and mortality. The evaluation of ILD in patients with CTD is complex because of the heterogeneity of the CTD spectrum, the various patterns and degrees of severity of ILD encountered, and because ILD can be identified at any point in time in these patients. A thorough - and optimally multidisciplinary - evaluation is needed when CTD patients develop ILD or when evaluating ILD patients for the presence of occult CTD. Determining whether ILD is associated with a preexisting CTD requires the exclusion of alternative etiologies, and thorough assessments of the clinical features of both the CTD and ILD. The detection of occult CTD in patients with presumed idiopathic interstitial pneumonia requires careful integration of clinical, serologic, and thoracic imaging and histopathologic features.