Table 3 Summary of diagnostic criteria
From: Spotlight on the diagnosis of extrinsic allergic alveolitis (hypersensitivity pneumonitis)
➢ | Routine, basic diagnostics: |
• | Case history: Exposure to relevant antigen(s) |
• | Exposure-related respiratory and systemic symptoms |
• | Specific IgG antibodies to relevant antigens (i.e. antigen-HSA-conjugates) |
• | Bibasilar end-inspiratory crackles (lower lung) |
• | Lung nodular, patchy and/or ground glass pattern in chest x-ray or HRCT |
• | Restrictive ventilation pattern (FVC, TLC) and reduced gas exchange parameters (TL,CO; Pa,O2) |
➢ | Facultative diagnostic parameter. |
If not all of the before-mentioned parameters are fulfilled at least one additional positive parameter is needed | |
• | Serial lung function testing during antigen exposure periods and days off (exhibiting changes as outlined under SIC as well as restitution of symptoms and impaired lung function during days off) or |
• | specific inhalative challenge test (exhibiting changes as outlined in Table 2) |
• | BAL showing lymphocytosis with ratio of CD4/CD8 < 1 or |
typical histopathological findings | |