Hypersensitivity pneumonitis symptoms and conditions

I am a Rheumatologist at private practice in PR. I was consulted on a patient who is recently diagnosed as pneumonitis, biopsy report is compatible with pneumonitis and refers it could be hypersensitivity pneumonitis or collagen disease. The patient refers that after she started singulair she noticed swelling of hands and general malaise that dissapeared when she D/C it. This happened by the same time as the pneumonitis. Has pneumonitis been reported with Singulair?

I have been on prednisone taper for about five months, starting at 40 mg for six weeks, and then tapering to 30 mg for six weeks, 20 for six weeks, and I am now down to 15 mg for macrodantin induced pulmonary fibrosis. I have had weight gain, bloating moon face, muscle cramping, hair loss, and mood swings. I will be glad to get off this drug, although it has helped me a lot. I also have hypersensitivity pneumonitis, and it does not help much for that. I will just have to move out of the area because I am very allergic to something and cannot find out what it is. The water retention and the moof face are the hardest to take. I also have had back pain since being on this, and I don't know for sure this is a side effect or not. I have heard of others who have had this and when they stopped the prednisone, their back pain went away. I will let you know when I am off in April.