Case Presentation:
Scleroderma encompasses a spectrum of related disorders, most of which share a characteristic clinical feature of skin thickening due to an excess of collagen fiber deposition. Serologic testing is helpful in confirming, but not excluding the diagnosis of systemic sclerosis (SSc). A 63‐year‐old white man presented with a 2‐month history of progressive dyspnea, worsening lower‐extremity edema and orthopnea. For The past month, he had noted a tightening of the skin on his face, hands, abdomen and thighs. He had nonproductive cough for the past 3 weeks, but denied hemoptysis. Ten months ago, he was diagnosed with osteoarthritis for which, he was taking over the counter analgesics. He had never smoked. On examination, he was hypertensive with mild generalized skin thickening. Bibasilar, fine, end inspiratory crepitations were audible on the respiratory examination. Laboratory evaluation demonstrated elevated blood urea nitrogen and creatinine (BUN 69, creatinine 4.6. BP 194/110). Mild proteinuria and trace blood were noted on urinalysis. A serology panel for ANA, antineutrophil cytoplasmic antibodies, anticentromere antibodies, and antitopoisomerase 1 (Scl‐70) antibodies was negative. A high degree of clinical suspicion prompted testing for anti‐RNA polymerase antibodies, which were positive. A skin and muscle biopsy demonstrated lymphocytic inflammation within the perimysial connective tissue around and within vessel walls, suggestive of vasculitis, without the evidence of myositis, confirming the diagnosis of systemic sclerosis. Pulmonary hypertension was noted on echocardiography. Computerized tomography of the chest revealed mild interstitial changes in lungs, bilateral small pleural effusion. The patient refused a renal biopsy. Hemodialysis and ACE inhibitor therapy were initiated. The patient continued to improve clinically and was discharged home with follow‐up appointments.
Discussion:
This case is unusual, as our patient lacked typical clinical symptoms and serologic features of scleroderma. He had no evidence of Raynaud's phenomenon or gastrointestinal involvement, which is typically present in 90% of patients with SSc. Anti‐RNA polymerase antibody was The only positive serologic marker, which is usually associated with an increased risk of renal crisis. He had evidence of interstitial lung with absent antitopoisomerase 1 antibody, which is usually associated with a higher risk for interstitial lung disease. Further, he presented with a scleroderma renal crisis, which is an uncommon initial presentation of SSc.
Conclusions:
Systemic sclerosis is a clinically heterogeneous systemic disorder and is associated with a wide array of serologic markers. The heterogeneous clinical phenolypes of systemic sclerosis make it a challenging diagnosis for clinicians. Typical clinical features should prompt the clinician to aggressively pursue the diagnosis, even if serological markers are initially negative.
Author Disclosure:
C. Singh, none; F. Irani, none; N. Kaur, none.