Lesson of the month 2: Dry skin, yellow nails and breathlessness.

Interstitial lung disease (ILD) is a common clinical problem, representing a group of diseases consisting of inflammation and progressive fibrosis of the lung. In some cases, an underlying cause is not identified; however, a significant proportion of ILD is associated with connective tissue disease (CTD). A detailed history and examination is the most important part of the assessment of patients with suspected ILD and will direct further investigation. This case illustrates the importance of identifying the symptoms and signs of CTD when assessing a patient with ILD. In addition, we describe an unusual presenting manifestation of yellow nails, which is not a recognised feature of CTD-ILD, but improved following immunomodulatory treatment for the overall condition. © Royal College of Physicians 2017. All rights reserved.