The diagnosis of pneumonitis requires blood tests, sputum tests and x-rays. Treatment of pneumonitis initially includes a course of antibiotics. If laboratory and other diagnostic tests show no proof of infections, then the diagnosis is likely lupus pneumonitis. This non-infectious pneumonitis is treated with high doses of corticosteroids. It is a chronic form of lupus pneumonitis and affects a relatively small number of people.
Diagnosis requires the exclusion of infection as a possible cause.
Besides lupus, there are other causes of chronic diffuse interstitial lung disease. Correct identification of the cause is required to accurately select the proper treatment. Chronic lupus pneumonitis scars the lung and decreased the lungs' ability to deliver oxygen to the blood. The diffusion capacity of the lung is a measurement of how readily oxygen moves through the lung and into the blood stream. It is usually reduced in chronic lupus pneumonitis.