Hypersensitivity pneumonitis related to medium-density fiberboard.

Pneumonitis due to hypersensitivity to wood fiber is mainly associated with the fungus that colonizes it. We present the case of a male affected with hypersensitivity pneumonitis in which the agent implicated was medium-density fiberboard, an engineered product whose main component is pine wood fiber. The causal agent was identified by means of a specific bronchial provocation test.