Which of the following collagen disorder is NOT commonly associated with pulmonary fibrosis
**Core Concept**
Collagen disorders, also known as autoimmune connective tissue diseases, are a group of conditions characterized by the formation of autoantibodies against various components of the extracellular matrix, including collagen. These disorders can lead to fibrosis, which is the scarring of tissues, including the lungs.
**Why the Correct Answer is Right**
Pulmonary fibrosis is a common complication of several collagen disorders, including systemic sclerosis (scleroderma), dermatomyositis, and rheumatoid arthritis. However, systemic lupus erythematosus (SLE) is less commonly associated with pulmonary fibrosis compared to these other conditions. This is because SLE is a more heterogeneous disease, and its manifestations can vary widely between patients. While SLE can cause lung involvement, including pneumonitis and pleuritis, pulmonary fibrosis is not as characteristic of this disease as it is of the other collagen disorders listed.
**Why Each Wrong Option is Incorrect**
**Option A:** Systemic sclerosis is a collagen disorder that is strongly associated with pulmonary fibrosis, as the disease process can lead to the deposition of collagen in the lungs, resulting in fibrosis and scarring.
**Option B:** Dermatomyositis is a collagen disorder that can also cause pulmonary fibrosis, although this is less common than in systemic sclerosis. However, the risk of pulmonary fibrosis is still higher in dermatomyositis than in SLE.
**Option C:** Rheumatoid arthritis is a collagen disorder that can cause pulmonary fibrosis, particularly in patients with a history of lung involvement or those who have undergone lung surgery.
**Clinical Pearl / High-Yield Fact**
When evaluating a patient with a collagen disorder and pulmonary symptoms, it is essential to consider the specific disease process and the likelihood of pulmonary fibrosis. A thorough clinical history, physical examination, and diagnostic testing can help guide the diagnosis and management of these complex conditions.
**Correct Answer:** D. Systemic lupus erythematosus.