title: [A case of hypersensitivity pneumonitis caused by inhalation of Mycobacterium avium from a home bath with a circulating water system].
abstract: A 26-year-old man presented with complaints of exertional dyspnea and cough. The patient has already been given corticosteroids at a previous hospital. Chest CT revealed small centrilobular nodules with diffuse ground-glass opacities in both lungs. Lung biopsy specimens at thoracoscopy revealed non-necrotizing granulomas, patchy foci of mononuclear cell infiltration and fibrous thickening of alveolar septa, and Masson's bodies in bronchioles. Sputum culture showed the growth of Mycobacterium avium complex (MAC). Culture of water from the bath tub of his home showed MAC. Administration of antituberculous drugs and corticosteroids, and avoidance of bathing at home resulted in the improvement of his symptoms and CT findings. We believe the case is hypersensitivity pneumonitis to MAC in an immunocompetent patient, simulating hot tub lung. Hypersensitivity pneumonitis caused by MAC is rare in Japan.
authors.affiliation: Department of Respiratory Medicine, Shizuoka General Hospital.
authors.forename: Hirotsugu
authors.initials: H
authors.lastname: Kenmotsu
authors.forename: Atsuro
authors.initials: A
authors.lastname: Honda
authors.forename: Tomohisa
authors.initials: T
authors.lastname: Baba
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Matsumoto
authors.forename: Izumi
authors.initials: I
authors.lastname: Shichi
authors.forename: Takashi
authors.initials: T
authors.lastname: Eto
authors.forename: Kazumori
authors.initials: K
authors.lastname: Arai
mesh_terms: D000328:Adult; D000542:Alveolitis, Extrinsic Allergic / Q000209:etiology* / Q000473:pathology; D001494:Baths / Q000009:adverse effects*; D006801:Humans; D016867:Immunocompromised Host; D008297:Male; D015269:Mycobacterium avium Complex / Q000302:isolation & purification*; D015270:Mycobacterium avium-intracellulare Infection / Q000150:complications* / Q000473:pathology; D014871:Water Microbiology