Table 2.
Diagnostic parameters of extrinsic allergic alveolitis
| Symptoms: | |
| • | Exposure (work)-related cough, chest tightness, dyspnea, fever, with latency period of several hrs |
| • | Progressive flu-like symptoms during the exposure periods (e.g. working week) with solution at days off |
| • | Dyspnea on exertion |
| • | Weight loss in the absence of any other reason |
| Clinical/physical examination: | |
| • | Fine bibasilar end-inspiratory crackles in advanced chronic forms clubbing and respiratory distress |
| Serology: | |
| • | Presence of high serum concentrations of antigen-specific IgG antibodies |
| Lung function testing: | |
| • | FVC < 80% predicted (below lower limit of normal) or |
| • | FVC < 70% pred. and/or TL,CO < 80% pred. or |
| • | TL,CO < 60% pred. or hypoxemia during exercise |
| Radiology: | |
| • | Abnormal chest x-ray (nodular, patchy and/or diffuse ground glass pattern) |
| • | Abnormal HRCT (ground glass, nodular and/ or patchy opacities, mosaic or UIP pattern |
| Serial lung function testing and clinical investigations during antigen exposure periods and days off (for minimal diagnostic changes see SIC below): | |
| Specific inhalation challenge (minimal changes after 5-12 hrs): | |
| • | FVC and TLC -15% |
| • | TL,CO -15% or Pa,O2 – 7 mmHg |
| • | New fine bibasilar end-inspiratory crackles |
| • | Systemic symptoms (temperature + 1°C and leukocytosis + 2.5 × 109/L) |