In 1979, Hunninghake and Fauci in their review entitled “Pulmonary Involvement in the Collagen Vascular Disorders,” suggested that this involvement is frequent in Sjögren s syndrome and can be manifested as pleurisy, interstitial fibrosis, desiccation of the tracheobronchial tree, and lymphoid interstitial disease. They also stated that the first two could be manifestations of the concomitant rheumatic disorder and that only desiccation of the tracheobronchial tree and lymphoid interstitial fibrosis are “specific” for Sjogren’s syndrome.
There have been several articles on the lungs and Sjogren’s syndrome since then. Only two deal with large populations of patients with primary Sjogren’s syndrome. Oxholm et al reported in their large series of 46 such patients that the most common functional abnormality was reduced pulmonary diffusing capacity. We have reported in a previous study of 22 patients with primary Sjogren’s syndrome that there are two distinct forms of respiratory involvement, ie, (1) “xerotrachea” manifested only by dry cough without any roentgenologic or functional abnormality, and (2) diffuse interstitial pulmonary disease. Pulmonary function in that study was evaluated only with spirometry and arterial blood gas levels. Three other studies deal with small numbers of patients with both primary and secondary Sjogren’s syndrome and stress airways obstruction as the most common abnormality. In this study, based on clinical, roentgenologic, functional, and histologic data, we suggest that primary Sjogren’s syndrome can frequently (75 percent) involve the respiratory system from the trachea and large airways to the small airways, pulmonary parenchyma, and pulmonary interstitium.
Involvement of the trachea and large airways results in their desiccation and presents with dry cough that can, at times, be very annoying. We had patients treated for “asthma,” “chronic bronchitis,” or even “tuberculosis” because of this cough before Sjogren’s syndrome was diagnosed. We can attribute this isolated symptom of dry cough that was the only abnormal respiratory manifestation in six of our patients (17 percent) to desiccation of the tracheobronchial tree (“xerotrachea”), since no other cause for the cough was found, and the desiccation of the airways was documented bronchoscopically. This has also been documented by other investigators in the past who have shown bronchial mucosal infiltration with mononuclear cells in similar patients. It is interesting that this group of patients cannot be detected with functional criteria, and therefore clinical evaluation is very valuable in their case.