A rare feature of systemic lupus erythematosus.
Estimated prevalence in S LE ranges from 0.5%-6%.
Associated with symptoms of shortness of breath, and often some chest pain when breathing deeply.
Chest X-rays and CAT scans of the thorax show small, clear lungs.
Pulmonary function tests demonstrate stiff lungs, with restrictive deficits.
Sometimes the diaphragm is elevated, reducing lung size.
Lack of good chest expansion and poor motion of the diaphragm are two possible reasons for the decreased lung function.
The severity of restrictive deficit does not correlate with SLE activity, disease duration, levels of ANA, anti-double-stranded DNA antibodies or C3 complement.
Generally the prognosis is good.
Treatment with steroids and immune suppressing medication may be needed.