A case of yellow nail syndrome with dramatically improved nail discoloration by oral clarithromycin.

An 80-year-old woman was admitted to our hospital with pneumonia and exacerbation of sinobronchial syndrome (SBS). She presented with yellow discoloration of the nail beds of all fingers and toes, and her nails were recognized as growing slowly. Chest X-ray revealed bronchiectasis in the bilateral lower lobe and bilateral pleural effusion. We diagnosed her as having yellow nail syndrome (YNS), based on the triad of yellow nails, lymphedema, and lung disease. After treatment with antibiotics [ampicillin/sulbactam and clarithromycin (CAM)] for pneumonia and SBS, her general condition improved, and the yellow nails disappeared in some fingers. When she was previously treated with 200 mg CAM for SBS, her yellow nails had not shown improvement. This time, her yellow nails improved after treatment with 400 mg CAM. The literature reports vitamin E, zinc, and topical corticosteroid plus active vitamin D3 to be effective in the treatment of yellow nails. Two studies have reported treatment for YNS using CAM, though they found a lack of efficacy. Thus, the present case is the first to report improved yellow nails using CAM alone. We conclude that not only SBS and lung disease but also YNS were improved by treatment with 400 mg CAM.