Bucillamine-induced yellow nail in Japanese patients with rheumatoid arthritis: two case reports and a review of 36 reported cases

Yellow nail syndrome is an idiopathic condition characterized by a triad consisting of yellow nail, lymphedema, and pulmonary manifestations. Thiol compounds such as D-penicillamine have been reported to be the major cause of drug-induced yellow nail syndrome in patients with rheumatoid arthritis (RA). We recently experienced two Japanese cases with RA who developed yellow nail under treatment with bucillamine, a thiol-containing anti-rheumatic drug developed and approved in Japan. We reviewed the literature for similar cases and identified 36 RA cases with bucillamine-induced yellow nail, mostly in Japanese medical journals. Most of these cases (90.3%) showed improvement of yellow nail after discontinuation of bucillamine, whereas lymphedema and pulmonary manifestations improved only in 30.8 and 35.0% of the patients, respectively.