Acute presentation: flu-like illness with cough;
Subacute: recurrent "pneumonia";
Chronic: exertional dyspnea, productive cough, and weight loss;
The exposure is to wood chips from living maple and oak trees, and the suspected antigens are Penicillium (three species), Paecilomyces sp., Aspergillus niger, Aspergillus sp., and Rhizopus sp. [See Reference Link] Three cases of HP were diagnosed in employees of a hardwood processing plant. Mold growth (Paecilomyces) was detected, and growth was promoted by drying the lumber in a kiln. [PMID 16621767
] See "Hypersensitivity pneumonitis."