[A boy highly suspected of hypersensitivity pneumonitis characterized by generalized mucosal lesions].

The case is a boy who developed progressive dyspnea and had since been followed over a long period time as a case of unknown fever without respiratory symptoms. He showed mucosal symptoms such as intraoral aphtha, eosinophilic pyuria and diarrhea and was clinically diagnosed as hypersensitivity pneumonitis. The affected child showed high levels of circulating immune complex, a decline in DLco on the respiratory function test and a decrease in CD 4/8 in bronchoalveolar lavage lymphocytes; furthermore, an antibody specific to Aureobasidium pullulans was positive in the precipitated antibody test. As for the immune function of the affected child during the follow-up, hypergammaglobulinemia and various immune abnormalities were observed. We thought the clinical feature of the affected child to be of pathophysiological value in dealing with unknown fever in childhood, so we reported our findings in this paper.