Fig. 1

A thoracic CT before admission revealed diffuse fine centrilobular nodules with patchy ground-glass opacities of the upper lung predominance (upper). After the admission, the pulmonary parenchymal involvements were spontaneously improved (middle). 15 h after the end of the provocation test, fine centrilobular nodules and patchy ground-glass opacities appeared again. Bronchial wall thickening with peripheral airspace consolidation in the right upper lobe were also visible (lower)