[Summer-type hypersensitivity pneumonitis in a family].

We encountered a family in which three of the five members (The parents and a daughter) had summer-type hypersensitivity pneumonitis that occurred in late summer. All three patients had a productive cough and shortness of breath. Chest roentgenograms of the mother and daughter (but not the father) showed diffuse small nodular shadows in both lung fields. Examination of bronchoalveolar lavage fluid from all three patients showed very high total cell counts, high percentages of T lymphocytes, and low ratios of CD4(+)-to-CD8+ cells. Microscopic examination of transbronchial biopsy specimens obtained from the daughter revealed infiltration of mononuclear cells with characteristic Masson bodies in alveolar septa, and granulomas in the interstitium. Both mother and daughter were positive for serum anti-Trichosporon cutaneum (serotype II) antibody, but the father, who was a current smoker was not. Thus, both mother and daughter were given the diagnosis of summer-type hypersensitivity pneumonitis, and in the father that diagnosis was strongly suspected.