Total leukonychia Q84.4

Complete white discoloration of one or more, also of all finger/foot nails without other changes to the nail plate. The nails lose their transparency due to a parakeratotic keratinization of the ventral horny layers of the nail plate.

Hereditary (OMIM 58 151600):

• "True Leukonychia": Autosomal dominant (autosomal recessive cases are also described) inherited, total white coloration of all 20 nails. Often epidermal cysts are also present. Caused by mutations of the PLCD1 gene (phospholipase C delta-1 gene on chromosome 3p22.2, which codes for the corresponding enzyme. Phospholipase C delta-1 was detected in the nail matrix and is partly responsible for the physiological growth of the matrix).
• Hereditary leukonychia may also be syndromally associated with keratoderma and deafness.

Acquired (idiopathic or as a result of other diseases):

• Chronic liver diseases(liver cirrhosis) - Leucopathy
• M. Addison
• Viral infections (e.g. HIV),

Half-and-half nails

1. Farooq M et al (2012) A novel mutation in the PLCD1 gene, which leads to an aberrant splicing event, underlies autosomal recessive leuconychia. Br J Dermatol 167:946-949
2. Ganesh A et al (2014) Idiopathic congenital true leukonychia totalis. Indian Dermatol Online J 5(Suppl 1): S65-66
3. Pielasinski-Rodríguez Ú et al (2012) Acquired total leukonychia in a patient with human immunodeficiency virus infection. Actas Dermosifiliogr 103:934-935
4. Turner MR (2013) Unilateral leukonychia and hair depigmentation in multifocal motor neuropathy. Neurology 81:1800-1801