Nephrogenic systemic fibrosis: a case report and review on Japanese patients.

Nephrogenic systemic fibrosis is a fibrosing disorder that affects patients with advanced renal dysfunction and is associated with gadolinium-based contrast media. As the number of reports increase, it is becoming clear that its clinical course and symptoms are various. We describe a 14-year-old boy and 71-year-old man with nephrogenic systemic fibrosis and review the Japanese cases documented thus far. In Japan, there are only 10 cases definitely associated with gadolinium, whereas over 500 cases have been recorded worldwide. We found a remarkable difference in clinical signs among Japanese cases. Some cases showed keratotic papules or plaques on the extremities. This group tended to develop symptoms after a shorter interval following gadolinium exposure. The remainder of the cases presented glossy and smooth surfaces, with symptoms tending to develop after a longer interval following their last gadolinium exposure. The discrepancies between the actual and the estimated number of patients, and the various clinical manifestations can be explained by the comparatively smaller dosage of gadolinium-based contrast agents commonly administrated in Japan, in contrast to the higher dosages administrated in the USA and Europe.