Agents causing extrinsic allergic alveolitis, specific inhalative challenge testing, and bronchoalveolar lavage cells. A. Mouldy hay causing farmer’s lung disease in the subject shown in Figure 1D and Figure 4
B. Bronchoalveolar lavage with extensive neutrophilia present six hours post challenge in an subject with pigeon breeder’s lung. C. Water and sediment of a humidifier water of a printing plant (of the subject shown in Figure 3). Microscopic examinations demonstrated a variety of bacteria and moulds in this specimen. D. Occupational type specific inhalative challenge test with mouldy hay (Figure 1A).