Apparent Leukonychia. The nails appear white because of abnormalities in the color of the nail bed and this is usually due to nail bed edema. Apparent leukonychia does not move distally with nail growth and the white discoloration fades with pressure. Nail bed pallor may be a non‐specific sign of anaemia, oedema or vascular impairment. It may occur in particular patterns which have become associated with certain conditions. It often due to drugs (chemotherapeutic agents) or systemic diseases (e.g. hypoalbuminemia)
is a term used to describe nails which are white proximally and normal distally and is attributed to cirrhosis, congestive cardiac failure or diabetes. Nail bed biopsy reveals only mild changes of increased vascularity.
describes nails where there is a proximal white zone and distal (20–60%) brownish sharp demarcation, the histology of which suggests an increase of vessel wall thickness and melanin deposition. It is seen in 9–50% of patients with chronic renal failure and after chemotherapy. It is unclear whether the variant Neapolitan nails, where there are bands of white, brown and red, is a version of half‐and‐half or Terry’s nails, or a feature of old age.
Muehrcke’s paired white bands
are parallel to the lunula in the nail bed, with pink between two white lines. They are commonly associated with hypoalbuminaemia, the correction of which by albumin infusion can reverse the sign. They have also recently been reported following placement of a left ventricular assist device in a patient with congestive heart failure.
- Terry’s 甲：肝硬化，郁血性心力衰竭或糖尿病
- Muehrcke 成对白色带甲：低白蛋白血症，心力衰竭患者中放置左心室辅助装置的患者
- Albright SD, Wheeler CE. Leukonychia: total and partial leukonychia in a single family with review of the literature. Arch Dermatol 1964;90:392–9.
- Grossman M, Scher RK. Leukonychia: review and classification. Int J Dermatol 1990;29:535–41.
- Holzberg M, Walker HK. Terry’s nails: revised definition and new correlations. Lancet 1984;i:896–9.
- Alam M, Scher RK, Bickers DR. Muehrcke’s lines in a heart transplant recipient. J Am Acad Dermatol 2001;44:316–17.