Leukonychia (Leukonychia Syndrome, White Nails Syndrome, and Milk Spots Syndrome) defines a medical condition in which the nails are discolored or simply presenting with white milky spots. It is derived from the Greek words leuko = “white,” and onychia “nails.” It is caused by a failure in the matrix of the nail to form normal nails. This is a physical characteristic that can be seen with numerous medical conditions (see Table L-2) but is most commonly associated with minor injuries, such as nail biting—it is harmless. There are four types of Leukonychia defined by the clinical presentation: (1) Leukonychia Totalis: which is characterized by whitening of the entire nail. It is often a clinical sign of hypoalbuminemia as seen in the Nephrotic Syndrome, liver failure, protein malabsorption, and protein-losing enteropathies. It is also observed as side-effects of sulfonamides antibiotic treatment. (2) Leukonychia Partialis: shows whitening of parts of the nail plate usually in form of small white dots. There are three different variations—punctate, transverse, and longitudinal leukonychia. Some more serious variations of leukonychia partialis may lead to leukonychia totalis. (3) Leukonychia Punctata: is also known as the “true” leukonychia. It is the most frequent presentation of leukonychia in which small white spots appear on the nails. Picking and biting of the nails are a prominent cause in young children and nail biters. Besides parakeratosis, air that is trapped between the cells may also cause this appearance. It is also caused by trauma and in most cases, the white spots appear on a single or a couple of fingers or toes. The suggested mechanism of action is injury to the matrix of the nail. In infancy, white spots disappear around 8 months of age that corresponds to the time necessary for nails to regrow completely. The pattern and number of spots may change as the nail grows. (4) Leukonychia Striata: also called transverse leukonychia, or Mees’ lines, that is defined as whitening or discoloration of the nail in bands or “stria” that run parallel from the lunula. This is commonly caused by physical injury or disruption of the nail matrix. It is also reported as a result of heavy metal poisoning, especially lead. It is also seen with chemotherapy and in patients affected with cirrhosis. This is the only form that can be inherited as an autosomal dominant pattern. Serious infections known for high fevers, measles, malaria, herpes, and leprosy may also cause the disease. The streaks can resolve spontaneously. There is a similar condition called Muehrcke’s lines (apparent leukonychia) which differs from leukonychia striata as the line fade away with digital compression and does not migrate with the growth of the nail. (5) Longitudinal Leukonychia: is far less common and features smaller 1 mm white longitudinal lines visible under the nail plate. It may be associated with Darier’s Disease.
N.B.: Darier’s Disease (Darier disease, Darier-White disease, Dyskeratosis Follicularis, Keratosis Follicularis) is an autosomal dominant disorder and is characterized ...