Primary Sjogren's Syndrome Presenting as Osteomalacia

Background: The most common renal disease in Sjogren’s syndrome (SjS) is tubulo-interstitial nephritis, which is responsible for renal tubular acidosis type 1 (RTA-1) in around 20% of patients. Osteomalacia rarely occurs as the first manifestation of a renal tubule disorder due to a connective tissue disease such as SjS. Results and conclusion: We report a 47-year-old woman with tubular acidosis induced osteomalacia. The tubular acidosis was a result of renal involvement in SjS. Improvement was obtained with vitamin D, calcium, and high-dose steroid therapy. These findings suggest that evidence for SjS should be sought in adult patients with unexplained osteomalacia and renal tubular acidosis, even in the absence of subjective sicca syndrome. Conversely, in patients with SjS, early investigation and treatment of renal tubular dysfunction may prevent future complications, such as osteomalacia.