Hypersensitivity pneumonitis induced by Konjak flour and powdered Hijikia fusiforme.

This is a report of a patient with occupational hypersensitivity pneumonitis (HP) caused by Konjak flour and powdered Hijikia fusiforme. A 56-year-old man had worked as a Konnyaku manufacturer for 38 years, and suffered from dyspnea on exertion. Konnyaku is a paste made from Konjak flour, powdered Hijikia fusiforme, quicklime, and powdered scallop shell. The diagnosis of HP was confirmed immunologically by the detection of serum precipitins to powdered Hijikia fusiforme, and by the positive result of in vitro lymphocytic proliferative response for Konjak flour using peripheral blood lymphocytes. To our knowledge, this is the first case report of Konnyaku manufacturer's lung.