You know that extrinsic allergic alveolitis is related to very specific occupations, such as farmers who develop an allergy to the mold in hay. If you were to experience lung problems you would have shortness of breath with various activities. If you only experience shortness of breath while sitting, but can still do vigorous activity no problem, then I would say that is chronic hyperventillation, or rather over breathing on a regular basis. If you are truly having severe shortness of breath, then you would feel it while sitting and walking around would become extremely difficult. People who have allergic alveolitis tend to get pneumonia a lot, or they get to the stage where they have shortness of breath all of the time, with a productive cough, and weight loss. If you are experiencing these kinds of symptoms you really should visit your doctor.