Evidence of autoimmunity, such as positive antinuclear antibody or latex fixation test or the presence of a collagen vascular disorder, suggests an idiopathic or a secondary type of usual interstitial pneumonia. Chronic eosinophilic pneumonias are often accompanied by peripheral blood eosinophilia. Sarcoidosis often results in hilar and paratracheal lymph node enlargement and may affect other organs. Bronchial asthma and allergic bronchopulmonary aspergillosis produce eosinophilia and airway obstruction rather than restrictive abnormalities. The most effective treatment is cessation of further exposure to the causative antigen.
Acute disease is self-limiting if additional exposure is avoided.
Socioeconomic factors may preclude a complete change of environment. Dust control or the use of protective masks to filter the causative dust particles in contaminated areas may be effective. Extensive cleaning of wet ventilation systems and corresponding work areas is also effective in some settings. Corticosteroids may be useful in severe acute or subacute cases but have not been shown to alter eventual outcome in chronic disease. Recurrence or progression of symptoms requires modification of this regimen.