Systemic sclerosis (SS) is a generalized connective tissue disorder characterized by: (1) skin thickening (scleroderma); (2) Raynaud’s phenomenon; (3) musculoskeletal manifestations; (4) visceral involvement especially of the lungs, heart, and kidneys. The lung is the fourth most commonly affected structure after skin, vessel and esophageal involvement. Systemic sclerosis has a 3:1 female to male distribution and presents most commonly in the 40 – 60 year old patients.

The chest radiograph is abnormal in about 25% - 50% of patients with established disease. The most common radiographic abnormality is widespread symmetric, basally predominant reticulonodular pattern which progresses to coarser reticulation. Gross fibrosis can cause airway destruction and bronchiectasis. The esophagus becomes dilated and may present as a significant ancillary finding in SS.

The main findings in HRCT are (1) ground glass opacification; (2) fine reticular pattern through to honeycombing, particularly subpleurally with traction bronchiectasis and subpleural cysts (1 to 3 cm diameter); (3) septal and subpleural lines; (4) small nodules particularly subpleural in location.

Pulmonary arterial hypertension is common in SS and occurs independently of lung fibrosis though both may occur together. There is an increased prevalence of lung carcinoma and the relative risk is the same as those patients with idiopathic pulmonary fibrosis (fibrosing aveolitis). Pneumonia is a recognized complication of SS and may secondary to aspiration from esophageal dysfunction.