Primary Sjögren's syndrome (pSS) is a chronic autoimmune disorder characterized by lymphocytic infiltrates in the lachrymal and salivary glands. Dryness of the eyes (keratoconjunctivitis sicca) and mouth (xerostomia) are the main clinical features. Histology shows lymphocytic infiltration and destruction of the affected glands. While the ocular manifestation of the disease, keratoconjunctivitis sicca, can be well diagnosed by objective tests (schirmer test, Rose bengale score), assessment of the manifestation in the salivary glands is more difficult. Besides histopathological examination of the minor salivary glands, parotid sialography, salivary gland scintigraphy, and unstimulated salivary flow examination have been accepted by the American-European Consensus Group as criteria for salivary gland involvement in SS. Sialography is considered to be the most reliable of the imaging methods. Salivary gland scintigraphy is very sensitive and especially usefull in early stages of the disease. Nevertheless, both imaging techniques are used by only minority of rheumatologists for diagnosis of SS because of the invasive character of sialography and the low specificity of scintigraphy. Another imaging techniques have been developed including computed tomography, magnetic resonance imaging (MRI), MR sialography, and ultrasonography. Ultrasonography of the salivary glands appears to be the most attractive imaging approach: it is an inexpensive commonly available noninvasive technique that does not cause complications and inconvenience to the patient. Sjögren's syndrome is considered primary in patients who have no underlying connective tissue disease. Investigations must be performed to document the ocular and oral dryness; to rule out connective tissue disease; and to confirm that the dryness is not due to other conditions such as diabetes mellitus, hypovolemia, sarcoidosis, infection, respiratory or renal insufficiency, smoking, or medications. These investigations include salivary flow measurement, sialochemistry, sequential salivary scintigraphy, and sialography using liposoluble or hydrosoluble contrast material. Histological examination of minor salivary gland biopsies may be the most specific investigation for diagnosing pSS.In recent years, ultrasonography has been described as a simple noninvasive tool for identifying salivary gland changes in patients with pSS, although the data are somewhat conflicting. Doppler waveform analysis was found useful for detecting blood flow abnormalities in the submandibular glands of patients with pSS compared to controls (13). Resistive and pulsatility indices of the facial artery were decreased in the patients, and responses to lemon stimulation were less marked than in the controls. Another study (14) evaluated blood inflow through the facial artery to the submandibular glands and through the external carotid artery to the parotids but failed to evaluate the transverse facial artery, which contributes to supply the parotid glands. Given the importance of parotid and submandibular glands involvement in pSS, we believe that the vascularization and B mode sonography should be evaluated routinely. More recently, a study has showed the importance to add ultrasonography of salivary glands in increasing the sensitivity for detecting pSS patients and suggest modifications of American-European Consensus Group (AECG) classification criteria.
Disclosure of Interest None declared