Premature onset of Sjögren's syndrome is prone to be complicated with renal tubular acidosis.

Sjögren's syndrome (SS) is a common systemic autoimmune disease. SS usually occurs among middle-aged women with a peak incidence age of approximately 50 years old. Kidney involvement is relatively uncommon in SS, which is mostly characterized as interstitial nephritis and may result in renal tubular acidosis (RTA). But premature onset of SS seems to be prone to RTA. Here we reported four cases of premature onset SS who developed into RTA at a relatively young age and three of whom suffered from severe osteomalacia. All of them shared a disease onset under age eighteen. Two of them presented hypokalemic periodic paralysis initially, one presented purpura and one endured xerophthalmia at first place. Three of them complicated with osteomalacia under age thirty. All the 4 cases didn't receive proper medical care in time due to a prolonged delay of diagnosis. We aim to raise the alarm over misdiagnosis/underdiagnosis of the disorder among young people.