pneumonitis

Please explain what pneumonitis is and what may have caused it? the patient lives in a MRMD institution so I am sure that this was not caused by mold or a fungus.  I am concerned that it may have to do with a medication that she was taking.  Please tell me more about pneumonitis.  Thank you.

[National Jewish]

Pneumonitis is often used interchangeably with pneumonia, but pneumonia usually implies an infectious cause, whereas pneumonitis usually implies a non-infectious cause. The infectious pneumonias can be caused by any of hundreds of bacteria, viruses, parasites and fungi. The non-infectious pneumonias are generally autoimmune or allergic and, not infrequently, of unknown cause. Pneumonitis can, indeed, be the result of an allergic drug reaction.
Given the wide range of causes of X-ray shadows that indicate pneumonia or pneumonitis, a careful evaluation by a physician knowledgeable about pneumonia/pneumonitis, such as a lung specialist or pulmonologist, is warranted. The likelihood of certain pneumonias is greater, depending on the living situation of an individual; for example, community-acquired vs. those that are hospital acquired.