Abstract
Amyotrophic lateral sclerosis (ALS) is a rare disease with a poor prognosis, and early diagnosis can be challenging.
We encountered a case of diffuse panbronchiolitis (DPB), suspected to be due to subclinical aspiration caused by ALS, that was refractory to low-dose macrolide therapy. A 69-year-old man presented to our hospital with complaints of cough and yellowish sputum. He had a history of sinusitis, and based on characteristic chest CT findings, was diagnosed with DPB and started on low-dose clarithromycin (CAM) therapy. His symptoms gradually improved, and the chest shadows resolved. After one year of CAM therapy, the treatment was discontinued. However, six months later, the same symptoms recurred, and CAM was restarted. This time, there was no improvement, and the patient experienced progressive weight loss, which eventually led to muscle weakness in his lower extremities. A brain MRI revealed no central nervous system lesions, and nerve conduction studies were normal, but needle electromyography showed characteristic findings consistent with ALS. We suspected that the recurrence of DPB was due to subclinical aspiration exacerbated by ALS. In cases of DPB with unexplained weight loss or muscle weakness, the possibility of coexisting ALS should be considered.
