Mechanic’s hands in a woman with undifferentiated connective tissue disease and interstitial lung disease – anti-PL7 positive antisynthetase syndrome: a case report

INTRODUCTION Interstitial lung disease can be idiopathic or occur in the setting of connective tissue diseases. In the latter case it requires a different treatment approach with a better prognosis. Interstitial lung disease can precede the onset of typical connective tissue disease features by many years, and therefore meticulous multidisciplinary follow-up is crucial. This case highlights the diagnostic challenge and the need for intensified attention for subtle clinical features when faced with interstitial lung disease in patients with characteristics of a hitherto undifferentiated connective tissue disease. CASE PRESENTATION A 44-year-old Caucasian woman presented to our pulmonology department with dyspnea, Raynaud's phenomenon and subtle swelling of fingers and eyelids. Laboratory analysis and autoantibody screening was negative. She was diagnosed with nonspecific interstitial pneumonia with a concurring undifferentiated connective tissue disease. After four years of stable disease, she presented with rapid pulmonary deterioration, myalgia, periorbital edema, arthritis and a cracked appearance of the radial sides of the fingers of both her hands. This clinical sign was recognized as mechanic's hands and a specific search for the presence of antisynthetase antibodies was performed. She was found to harbor anti-threonyl-tRNA synthetase antibodies. A diagnosis of antisynthetase syndrome was made and she was treated with glucocorticoids and immunosuppressives. CONCLUSIONS This case highlights the difficulty in fine-tuning the diagnosis when confronted with a patient with interstitial lung disease and the suspicion of an underlying, yet undifferentiated connective tissue disease. There is a strong need for clinical multidisciplinary follow-up of these patients, with a high level of alertness to rare and specific clinical signs. The diagnosis of the underlying connective tissue disease profoundly influences the management of the interstitial lung disease. Recent data stress that identification of the autoantibody specificity allows for further prognostic stratification and therefore should be pursued.