A 73-year-old woman was referred to our hospital because of a 1-month history of dry cough and dyspnea on exertion and an 8-month history of bullous eruptions, which had not improved after treatment with steroid ointment (difluprednate) and oral antihistamine (azelastine). Physical examination disclosed neither finger clubbing nor swollen lymph nodes, but fine crackles were detected bilaterally on chest auscultation. Laboratory tests revealed a normal blood count and routine chemistry levels. The serum levels of KL-6 and surfactant protein-A, markers for interstitial pneumonia, were 1,235 U/mL (normal value <500 U/mL) and 99.5 ng/mL ( <43.6 ng/mL), respectively. There was a positive antinuclear factor of 1:640 (centromere pattern), but the patient did not reveal any clinical findings of CREST syndrome. In addition, tests were negative for all other specific antibodies, such as anti SS-A and SS-B antibodies, antineutrophilic cytoplasmic antibodies, anti-DNA antibodies, and anti-Jo-1, anti-Scl-70, and anticyclic citrullinated peptide antibodies. Chest CT scans are shown in Figure 1.