Titanium Dioxide in Toothpaste Causing Yellow Nail Syndrome.

Yellow nail syndrome (YNS) is an uncommon disorder, the classic triad of which consists of yellow nails, lymphedema, and respiratory symptoms. Few pediatric cases have been reported. We report a 9-year-old girl with yellowish nail discoloration for 1 year accompanied by respiratory symptoms, including chronic cough, recurrent pneumonia, bronchiectasis, and chronic sinusitis. The patient was diagnosed with YNS. Knowing that a relationship between YNS and titanium has been reported, we collected her nail clippings and detected titanium in them by energy dispersive radiograph fluorescence. This patient's titanium exposure may have come from her habit of swallowing children's toothpaste. With meticulous avoidance of swallowing toothpaste, she had amelioration of her yellow nail discoloration as well as diminution of her respiratory symptoms. We reevaluated her nail clippings for titanium 3 years later, and no titanium was detected. This observation suggests that avoiding titanium exposure could alleviate the symptoms of YNS. This is the first report of YNS in a pediatric patient that demonstrates a relationship between YNS and titanium. We review the previous reports of pediatric patients with YNS.