Yellow lunulae with fluorescence after tetracycline therapy.

Yellow lunulae with yellow fluorescence under Wood's lamp examination developed in a patient treated with a high-dose tetracycline hydrochloride regimen for cystic acne after one month of therapy. The clinical findings in other causes of yellow nail pigmentation are reviewed. The Wood's lamp examination is useful in distinguishing tetracycline-induced yellow nails from other causes of yellow nail pigmentation and may be helpful in determining patient compliance with tetracycline hydrochloride regimens of 1 g or more daily.