Organic Dust Toxic Syndrome-Reply

Abstract

In Reply. —We appreciate the interest of Dr Aven in our report of an outbreak of organic dust toxic syndrome among young adults. We endeavored to make clear that organic dust toxic syndrome is not the consequence of an immunologic inflammatory reaction. Rather, it is a dust-related illness in which high concentrations of a large variety of fungi and thermophylic actinomyces induce a direct inflammatory (toxic) response in the lung. The primary differential diagnosis is, however, with a form of hypersensitivity pneumonitis such as farmer's lung disease. This diagnosis was excluded by negative serological responses to the standard panel of fungal and bacterial antigens that have been associated with this disease, as well as to the extract of straw. Although not foolproof, the latter is the method by which Pepys originally identified the cause of hypersensitivity pneumonitis (extrinsic allergic alveolitis). During the investigation of the outbreak, we considered the advisability