Table 8. Differential diagnosis of extrinsic allergic alveolitis (EAA) and organic dust toxic syndrome (ODTS) [354].

Features	EAA	ODTS
Exposure	Various allergens	Endotoxins, high exposure
Incidence	2 – 30 / 10,000	10 – 100 / 10,000
Latency	4 – 8 hours	4 – 12 hours
Auscultation	End-expiratory rales on both sides basal	Normal, possibly rattling noises
Lung function	Restriction (rarely obstruction, DLCO reduced	Normal (possible restriction)
Precipitins	Often specific IgG	Mostly negative