Review Question - QID 216257

This patient's persistent dry cough, description of Raynaud phenomenon (swelling and pain in her fingers during cold weather), history of autoimmunity (i.e., vitiligo) and acid reflux, and thickened and indurated skin on physical exam are consistent with a diagnosis of scleroderma. Interstitial pulmonary fibrosis is a common complication of scleroderma that would explain this patient's dry cough and fine crackles on auscultation.

Scleroderma, also known as systemic sclerosis, is an autoimmune condition characterized by inflammation that leads to progressive tissue fibrosis through excessive collagen deposition. There are 2 main types of scleroderma: limited cutaneous and diffuse. In diffuse scleroderma, various organ systems may be involved including the renal system (acute renal failure or scleroderma crisis), gastrointestinal system (esophageal dysmotility, gastroesophageal reflux disease, and small bowel bacterial overgrowth), pulmonary system (interstitial fibrosis or pulmonary hypertension), and cardiovascular system (cor pulmonale). Interstitial fibrosis is a well-known complication of diffuse scleroderma and typically presents as a chronic dry cough and/or progressive dyspnea, while physical exam findings include fine bibasilar crackles (sometimes described as resembling velcro). The optimal treatment for interstitial fibrosis secondary to scleroderma is not yet known, but the best available evidence shows immunosuppressive therapy with mycophenolate mofetil, cyclophosphamide, or azathioprine is the most appropriate initial treatment.

Adnan review scleroderma. They note that it is more common in women and is a systemic connective tissue disorder. They recommend making the diagnosis based on both the physical exam and laboratory testing.

Figure A is a physical exam finding demonstrating thickening and induration of the skin, which can sometimes take on a shiny appearance as it is pulled taut over bone, namely in the hands and feet.

Incorrect Answers:
Answer 1: Asthma can sometimes present in patients as only a chronic dry cough that typically occurs at night. Spirometry and bronchoprovocation tests with methacholine are most reliable for diagnosis. On physical exam, asthma is associated with wheezing on auscultation, rather than bibasilar crackles as in this patient.

Answer 2: Chronic obstructive pulmonary disease (COPD) typically manifests with chronic cough that can be productive or dry and dyspnea on exertion, generally secondary to chronic bronchitis or emphysema. On exam, patients may have a barrel chest, end-expiratory wheezing, muffled breath sounds, jugular venous distention, and may use accessory muscles of respiration. This patient's respiratory symptoms are less likely due to COPD as her history does not include the main risk factors, namely tobacco use, air pollution, occupational exposure, or cystic fibrosis.

Answer 3: Gastroesophageal reflux disease (GERD) may manifest as a dry cough in many patients with the condition, but it is usually associated with symptoms of heartburn and regurgitation. The major mechanism thought to be responsible for GERD-associated cough is the esophageal-tracheobronchial cough reflex: acid irritation of the esophagus has been found to result in vagally mediated reflexes causing bronchoconstriction. This patient's GERD is adequately treated with a proton pump inhibitor (omeprazole), and the presence of bibasilar crackles suggests a different cause for her respiratory symptoms. Of note, GERD is very common in patients with scleroderma.

Answer 5: Medication side effect of chronic dry cough is most associated with the use of angiotensin-converting enzyme (ACE) inhibitors. This common side effect is thought to be caused by the build-up of bradykinin, substance P, and prostaglandins, as ACE is involved in the breakdown of bradykinin and substance P. Although this patient is taking medication for her hypertension, she is taking a calcium channel blocker, which would not cause dry cough as a side effect. Of note, most patients with scleroderma should be on an ACE inhibitor as it is nephroprotective. It is the drug of choice for scleroderma renal crisis.

Bullet Summary:
Diffuse scleroderma is an autoimmune condition characterized by sclerosis of the skin and involvement of various organ systems, with interstitial fibrosis being a common manifestation of pulmonary involvement.