While salivary gland ultrasound has become popular for diagnosing Sjogren’s syndrome, doctors should be aware that two other conditions can give very similar results, US researchers say.

The salivary glands of patients with sarcoidosis or amyloidosis can look the same as Sjogren’s patients on imaging, warn rheumatologists from Boston Medical Centre.

“Unfortunately, there does not appear to be any specific salivary gland ultrasound findings to help distinguish Sjogren’s syndrome from sarcoidosis and [immunoglobulin light chain] AL amyloidosis,” they wrote in Arthritis Care and Research.

In their study, which they believed was the first to characterise salivary ultrasound results from patients with sarcoidosis or amyloidosis, the team compared imaging results from 21 patients with known Sjogren’s against 27 patients with sarcoidosis and 22 with AL amyloidosis.