 | This article needs more reliable medical references for verification or relies too heavily on primary sources .(October 2014) |  |
| Leukonychia | |
|---|---|
| Other names | White nails or Milk spots [1] |
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| Specialty | Dermatology |
Leukonychia (or leuconychia) is a medical term for white discoloration appearing on nails. [2] It is derived from the Greek words leuko 'white' and onyx 'nail'. The most common cause is injury to the base of the nail (the matrix) where the nail is formed.
This condition consists of a whitening of the entire nail and mostly likely occurs on all nails. Whitening of one, and only one, entire nail is not recognized as a symptom of leukonychia totalis but as a likely result of mechanical trauma. Leukonychia totalis may be a clinical sign of hypoalbuminaemia (low albumin), which can be seen in nephrotic syndrome (a form of kidney failure), liver failure, protein malabsorption and protein-losing enteropathies. A genetic condition or a side effect from taking sulphonamides (a family of antibiotics) can also cause this appearance. By 2011, only 6 cases of non-hereditary leukonychia totalis were published. [3]
In familial cases of leukonychia totalis, this condition is caused by mutations in the PLCD1 gene, in chromosome 3p22.2, this mutation shows an autosomal dominant pattern of inheritance, but in some cases, this condition may be autosomal recessive. [4]
This condition consists of a whitening of parts of the nail plate in the form of small white dots. There are three different variations of partial leukonychia; punctate, transverse and longitudinal leukonychia. Some of the more serious variations of leukonychia partialis may lead to leukonychia totalis. [5]
Leukonychia striata, transverse leukonychia, or Mees' lines are a whitening or discoloration of the nail in bands or "stria" that run parallel to the lunula (nail base). This is commonly caused by physical injury or disruption of the nail matrix. Common examples include excessive biting or tapping of the nails, trauma or injury from accidents involving doors or windows, and extensive use of manicure. [6] It may also occur in great toenails as a result of trauma from footwear. Alternatively, the condition can be caused by heavy metal poisoning, most commonly by lead. [7] Finally, it can be caused by cirrhosis of the liver or chemotherapy. [8]
The tendency toward leukonychia striata is sometimes inherited in an autosomal dominant fashion. In other cases, it can be attributed to vigorous manicuring and trauma aforementioned, or to a wide variety of systemic illnesses. Serious infections known for high fevers, measles, malaria, herpes, and leprosy may also cause this condition. In many patients, there is no obvious cause, and the streaks resolve spontaneously. [9]
There is a similar condition called Muehrcke's lines (apparent leukonychia) which differs from leukonychia in that the lines fade with digital compression and do not migrate with the growth of the nail. [10]
Also known as "true" leukonychia, this is the most common form 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. [5] It is also caused by trauma. In most cases, when white spots appear on a single or a couple of fingernails or toenails, the most common cause is injury to the base (matrix) of the nail. When this is the case, white spots disappear after around eight months, which is the amount of time the nails take to regrow completely. The pattern and number of spots may change as the nail grows. [11]
Longitudinal leukonychia is far less common and features smaller 1mm white longitudinal lines visible under the nail plate and perpendicular to the nail bed. It may be associated with Darier's disease. [5]
Apparent leukonychia is caused by changes in the nail bed that are visible through the nail plate. A number of patterns of apparent leukoncychia, including Terry's nails, half-and-half (Lindsay's) nails, and Muehrcke's lines, have been classically characterized. [12]
It is harmless and most commonly caused by minor injuries, such as nail biting, or may occur while the nail is growing. Some people suggest that it also may be caused by calcium deficiency, [13] although this is not backed up by research. Leukonychia occurs most commonly in healthy individuals, and is unrelated to any known nutritional or physiological deficiency. [5] When caused by injury the marks will disappear as the nail grows outwards. While there are various sources that link dietary needs or vitamin deficiency with recurrent leukonychia, [14] this notion has been challenged by some medical researchers. [15]
Other possible reasons for this problem can be linked to:
A doctor will take a thorough medical history, and may take blood tests as well as examining liver and kidney function. Intracellular (red blood cell) assays are more sensitive than tests for plasma levels. [18]
Improvements have been reported from treating malnutrition associated with zinc deficiency and other minerals. [19] [20]
Rhabdomyolysis is a condition in which damaged skeletal muscle breaks down rapidly, often due to high intensity exercise over a short period. Symptoms may include muscle pains, weakness, vomiting, and confusion. There may be tea-colored urine or an irregular heartbeat. Some of the muscle breakdown products, such as the protein myoglobin, are harmful to the kidneys and can cause acute kidney injury.
A nail is a protective plate characteristically found at the tip of the digits of all primates, corresponding to the claws in other tetrapod animals. Fingernails and toenails are made of a tough rigid protein called alpha-keratin, a polymer also found in the claws, hooves and horns of vertebrates.
A nail disease or onychosis is a disease or deformity of the nail. Although the nail is a structure produced by the skin and is a skin appendage, nail diseases have a distinct classification as they have their own signs and symptoms which may relate to other medical conditions. Some nail conditions that show signs of infection or inflammation may require medical assistance.
Darier's disease (DD) is a rare, genetic skin disorder. It is an autosomal dominant disorder, that is, if one parent has DD, there is a 50% chance than a child will inherit DD. It was first reported by French dermatologist Ferdinand-Jean Darier in 1889.
Calcinosis cutis is an uncommon condition marked by calcium buildup in the skin and subcutaneous tissues. Calcinosis cutis can range in intensity from little nodules in one area of the body to huge, crippling lesions affecting a vast portion of the body. Five kinds of the condition are typically distinguished: calciphylaxis, idiopathic calcification, iatrogenic calcification, dystrophic calcification, and metastatic calcification.
Hyperpigmentation is the darkening of an area of skin or nails caused by increased melanin.
Palmoplantar keratodermas are a heterogeneous group of skin disorders characterized by abnormal thickening (scleroderma) of the stratum corneum of the palms and soles.
Beau's lines are deep grooved lines that run from side to side on the fingernail or the toenail. They may look like indentations or ridges in the nail plate.
Onychomycosis, also known as tinea unguium, is a fungal infection of the nail. Symptoms may include white or yellow nail discoloration, thickening of the nail, and separation of the nail from the nail bed. Fingernails may be affected, but it is more common for toenails. Complications may include cellulitis of the lower leg. A number of different types of fungus can cause onychomycosis, including dermatophytes and Fusarium. Risk factors include athlete's foot, other nail diseases, exposure to someone with the condition, peripheral vascular disease, and poor immune function. The diagnosis is generally suspected based on the appearance and confirmed by laboratory testing.
Onycholysis is a common medical condition characterized by the painless detachment of the nail from the nail bed, usually starting at the tip and/or sides. On the hands, it occurs particularly on the ring finger but can occur on any of the fingernails. It may also happen to toenails.
Mees' lines or Aldrich–Mees lines, also called leukonychia striata, are white lines of discoloration across the nails of the fingers and toes (leukonychia).
Necrolytic migratory erythema is a red, blistering rash that spreads across the skin. It particularly affects the skin around the mouth and distal extremities; but may also be found on the lower abdomen, buttocks, perineum, and groin. It is strongly associated with glucagonoma, a glucagon-producing tumor of the pancreas, but is also seen in a number of other conditions including liver disease and intestinal malabsorption.
Muehrcke's nails or Muehrcke's lines are changes in the fingernail that may be a sign of an underlying medical condition. The term refers to a set of one or more pale transverse bands extending all the way across the nail, parallel to the lunula. In contrast to Beau's lines, they are not grooved, and in contrast to Mees' lines, the thumb is usually not involved.
Melanonychia is a black or brown pigmentation of a nail, and may be present as a normal finding on many digits in Afro-Caribbeans, as a result of trauma, systemic disease, or medications, or as a postinflammatory event from such localized events as lichen planus or fixed drug eruption.
Hapalonychia, is a condition in which a toenail or fingernail nail becomes soft and thin, causing it to easily bend or break. This can result from an inherited condition, malnutrition, or debility.
In racquet nails, the nail plate is flattened, the end of the thumb is widened and flattened, and the distal phalanx is abnormally short. In racquet nails, the width of the nail bed and nail plate is greater than their length. The condition is painless and asymptomatic.
Onychoschizia, also known as nail splitting and brittle nails, is a splitting of the free-edged tip of the nail. There is also often a longitudinal split in addition to the separation of keratin layers.
Non scarring hair loss, also known as noncicatricial alopecia is the loss of hair without any scarring being present. There is typically little inflammation and irritation, but hair loss is significant. This is in contrast to scarring hair loss during which hair follicles are replaced with scar tissue as a result of inflammation. Hair loss may be spread throughout the scalp (diffuse) or at certain spots (focal). The loss may be sudden or gradual with accompanying stress.
Acrokeratosis verruciformis is a rare autosomal dominant disorder appearing at birth or in early childhood, characterized by skin lesions that are small, verrucous, flat papules resembling warts along with palmoplantar punctate keratoses and pits. However sporadic forms, whose less than 10 cases have been reported, presents at a later age, usually after the first decade and generally lack palmoplantar keratoses. Whether acrokeratosis verruciformis and Darier disease are related or distinct entities has been controversial, like Darier's disease, it is associated with defects in the ATP2A2 gene. however the specific mutations found in the ATP2A2 gene in acrokeratosis verruciformis have never been found in Darier's disease.
Familial partial lipodystrophy, also known as Köbberling–Dunnigan syndrome, is a rare genetic metabolic condition characterized by the loss of subcutaneous fat.
They may also be caused by zinc or albumin deficiency, which is curable.
The results showed there was no correlation between calcium or zinc intake scores and leukonychia.
