It is best to identify the cause of Sicca.
If one has + blood work, at least a + ANA, then one can assume some autoimmune process. A positive SSA or SSB usually clinches the diagnosis....but, again it depends on your doctor.
It IS important. Some neuropathies are autoimmune and Sjogren's is known for small fiber neuropathy. To substantiate aggressive treatment, one must have an inflammatory etiology.
Seronegative Sjogrens, with all the other criteria, could be prodromal....then again, maybe not.
I would want to know why I had sicca, not just assuming it was Sjogren's.