Shrinking lung syndrome in systemic lupus erythematosus and Sjogren's syndrome

Shrinking lung syndrome (SLS) is a rare complication of systemic lupus erythematosus (SLE) characterized by unexplained dyspnea, a restrictive pattern on pulmonary function tests, and an elevated hemidiaphragm. A total of 59 cases are reported in literature including the current case. The mean age of these patients is 36.85 years (range, 15-61 years), and the female-to-male ratio is 6:1. This disorder is seen primarily during the later stages of SLE. The most common presenting features include dyspnea and pleuritic chest pain. Myositis has been reported in only 8 of 59 patients (13%). Diagnosis is made with chest x-ray showing an elevated hemidiaphragm and a restrictive pattern on pulmonary function testing without any evidence of interstitial lung disease along with decreased transdiaphragmatic pressure (Pdi). Corticosteroids are the most common method of treatment. Immunosuppressive therapy, beta-agonists, and theophylline are used in those resistant to steroids. The prognosis is generally good. This article reports the case of a 22-year-old man presenting with a 7-month history of dry mouth and dry eyes accompanied by increasing difficulty in breathing, progressing to dyspnea at rest. The patient's history included bilateral parotid gland swelling and nephrotic syndrome diagnosed 4 years earlier. Pertinent physical and laboratory findings included positive Schirmer's test results; bilateral parotid gland enlargement; bibasilar lung crackles; synovitis of the second and third proximal interphalangeal joints; a positive antinuclear antibody (Ro/SSA), Sm, and anticardiolipin antibodies; and elevated right hemidiaphragm on chest x-ray. Pulmonary function tests demonstrated restrictive lung disease with normal high-resolution computerized axial tomography. A dramatic response to oral prednisone (60 mg daily) was observed in all of the patient's complaints in a matter of several days. A diagnosis of SLE with secondary Sjogren's syndrome (SS) and SLS was made. Although SLS has been reported in association with SLE, there has been only one previous report of SLS in SLE/SS overlap syndrome. Early recognition with appropriate treatment can decrease the morbidity associated with this rare syndrome.