A few tests
Generally, checking labs is helpful since patients with sjogren's almost always have one of two autoantibodies (ssa, ssb) present.
Ssa, ssb also present in lupus but when only ssa or ssb is pos, sjogren's is a top consideration. Doctors can also test for sicca symptoms(decreased tear production with a paper strip put on lower eye
lid.Most definitive test is minor salivary gland biopsy