Inherited leukonychia totalis is a rare medical oddity, striking in appearance. It carries no connotation of disease, and has usually behaved as a simple, dominant characteristic.1 It has had brief reference in the general medical literature. In contrast, noninherited, incomplete leukonychia—either as white spots or transverse streaks of white—has been repeatedly described since 1646 and has acquired an abundance of folklore names: gift spots, lies, sweethearts, to name a few. Etiologies have been numerous: trauma, heavy-metal poisoning, acute "rhumatism," typhoid fever, ulcerative colitis, myocardial infarction, and many others.2 Both forms of leukonychia are the result of imperfect cornification (incomplete keratinization) of the horny cells of the nail plate.3
"Apparent" leukonychia, in which the translucent nail plate appears white, has been described most often in dystrophic diseases of the extremities (leprosy, for instance)4 and, more commonly, in cirrhosis of the livers.5 In these conditions, morphological changes in the nail bed give
HARRINGTON JF. White Fingernails. Arch Intern Med. 1964;114(2):301–306. doi:10.1001/archinte.1964.03860080151017
Customize your JAMA Network experience by selecting one or more topics from the list below.