Organic dust toxic syndrome

Definition

Acute, non-allergic, flu-like illness after heavy inhalation of organic dust (e.g. grain, mouldy hay, wood chips).

Grain silos, farming, hog confinement, mushroom production

Pathogenesis

Caused by inhalation of organic dust contaminated by microrganisms especially gram negative bacteria and thermophillic fungi. Cell wall derived endotoxins, mycotoxins and microbial products; not immune-mediated (distinguishes from hypersensitivity pneumonitis).

Cytokines and complement Cascade. Not immunological

Clinical features

Fever, chills, myalgia, malaise, cough, chest tightness; occurs 4–12 hrs after exposure.

Investigations

Normal chest X-ray and lung function; neutrophilia common, no specific antibodies

Prognosis

Self limiting

No antibiotics or steroids

List 3 inhalation fevers

1. Metal fume fever

2. Polymer fume fever

3. Organic dust toxic syndrome