Muehrcke's nails or Muehrcke's lines (
apparent leukonychia striata) are changes in the
fingernail
A nail is a claw-like plate found at the tip of the fingers and toes on most primates. Nails correspond to the claws found in other animals. Fingernails and toenails are made of a tough protective protein called alpha-keratin, which is a polymer. ...
that may be a
sign
A sign is an object, quality, event, or entity whose presence or occurrence indicates the probable presence or occurrence of something else. A natural sign bears a causal relation to its object—for instance, thunder is a sign of storm, or me ...
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
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.Freedberg, et al. (2003). ''Fitzpatrick's Dermatology in General Medicine''. (6th ed.). McG ...
, they are not grooved (no 3-dimensional deformity), and in contrast to
Mees' lines
Mees' lines or Aldrich–Mees lines, also called leukonychia striata, are white lines of discoloration across the nails of the fingers and toes (leukonychia).
Presentation
They are typically white bands traversing the width of the nail. As the ...
, the thumb is usually not involved.
Muehrcke's lines are a strong indicator of
hypoalbuminemia
Hypoalbuminemia (or hypoalbuminaemia) is a medical sign in which the level of albumin in the blood is low. This can be due to decreased production in the liver, increased loss in the gastrointestinal tract or kidneys, increased use in the body, or ...
, which can result from a variety of different causes.
The lines are actually in the vascular bed underneath the nail plate. As such, they do not move with nail growth, and disappear when pressure is applied to the nail (blanching the underlying nail bed): this distinguishes them from "true leukonychia striata" such as Mees' lines.
As in
Terry's
Terry's is a British chocolate and confectionery maker, formerly based in York, England, until 2005, and re-established in 2019 as Terry's Chocolate Co and based in London. The company was founded in 1767. The company's headquarters and fact ...
and
half-and-half nails, the pattern is thought to be formed by bands of localized edema exerting pressure on the surrounding capillaries.
Physiology
The appearance of Muehrcke's lines is associated
specifically with marked
hypoalbuminemia
Hypoalbuminemia (or hypoalbuminaemia) is a medical sign in which the level of albumin in the blood is low. This can be due to decreased production in the liver, increased loss in the gastrointestinal tract or kidneys, increased use in the body, or ...
(serum albumin ≤ 2.2 g/dL) indicating decreased protein synthesis, which may occur during periods of metabolic stress (e.g. systemic infection, trauma,
AIDS
Human immunodeficiency virus infection and acquired immunodeficiency syndrome (HIV/AIDS) is a spectrum of conditions caused by infection with the human immunodeficiency virus (HIV), a retrovirus. Following initial infection an individual m ...
,
chemotherapy
Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs (chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemotherap ...
), or in
hypoalbuminemic states such as the
nephrotic syndrome
Nephrotic syndrome is a collection of symptoms due to kidney damage. This includes protein in the urine, low blood albumin levels, high blood lipids, and significant swelling. Other symptoms may include weight gain, feeling tired, and foamy ...
or
dietary protein deficiency. They are also seen in patients with end-stage kidney disease on
hemodialysis
Hemodialysis, also spelled haemodialysis, or simply dialysis, is a process of purifying the blood of a person whose kidneys are not working normally. This type of dialysis achieves the extracorporeal removal of waste products such as creatinin ...
,
Hodgkin's disease
Hodgkin lymphoma (HL) is a type of lymphoma, in which cancer originates from a specific type of white blood cell called lymphocytes, where multinucleated Reed–Sternberg cells (RS cells) are present in the patient's lymph nodes. The condition wa ...
,
pellagra
Pellagra is a disease caused by a lack of the vitamin niacin (vitamin B3). Symptoms include inflamed skin, diarrhea, dementia, and sores in the mouth. Areas of the skin exposed to either sunlight or friction are typically affected first. Over t ...
, and
sickle cell anaemia
Sickle cell disease (SCD) is a group of blood disorders typically inherited from a person's parents. The most common type is known as sickle cell anaemia. It results in an abnormality in the oxygen-carrying protein haemoglobin found in red blo ...
.
The lines remain visible as long as protein intake is inadequate or synthesis is impaired, and they should disappear upon return to normal function.
In extreme conditions, Muehrcke's lines may also arise from physical changes in peripheral circulation: one case study reported appearance of the lines in a healthy subject following ascent to 8,848 meters (29,029 ft) on
Mount Everest
Mount Everest (; Tibetan: ''Chomolungma'' ; ) is Earth's highest mountain above sea level, located in the Mahalangur Himal sub-range of the Himalayas. The China–Nepal border runs across its summit point. Its elevation (snow heig ...
.
History
Muehrcke's lines were described by American physician
Robert C. Muehrcke (1921–2003) in 1956. In a study published in
BMJ
''The BMJ'' is a weekly peer-reviewed medical trade journal, published by the trade union the British Medical Association (BMA). ''The BMJ'' has editorial freedom from the BMA. It is one of the world's oldest general medical journals. Origina ...
, he examined patients with known chronic hypoalbuminemia and healthy volunteers, finding that the appearance of multiple transverse white lines was a highly specific marker for low serum albumin (no subject with the sign had SA over 2.2 g/dL), was associated with severity of the underlying condition, and disappeared upon successful treatment (corticosteroids in nephrotic syndrome) or direct infusion of
HSA.
See also
*
Mees' lines
Mees' lines or Aldrich–Mees lines, also called leukonychia striata, are white lines of discoloration across the nails of the fingers and toes (leukonychia).
Presentation
They are typically white bands traversing the width of the nail. As the ...
– a similar appearance, except the lines are in the nail and move as the nail grows
*
Half and half nail
Half and half nails (also known as "Lindsay's nails") show the proximal portion of the nail white and the distal half red, pink, or brown, with a sharp line of demarcation between the two halves.James, William; Berger, Timothy; Elston, Dirk (2005) ...
s
*
Terry's nails
Terry's nails is a physical condition in which a person's fingernails or toenailsFreedberg, et al. (2003). ''Fitzpatrick's Dermatology in General Medicine''. (6th ed.). McGraw-Hill. . appear white with a characteristic "ground glass" appearance wit ...
*
List of cutaneous conditions
Many skin conditions affect the human integumentary system—the organ system covering the entire surface of the body and composed of skin, hair, nails, and related muscle and glands. The major function of this system is as a barrier against t ...
References
Bibliography
*
*James, William; Berger, Timothy; Elston, Dirk (2005). ''Andrews' Diseases of the Skin: Clinical Dermatology''. (10th ed.). Saunders. .
*
Muehrcke's Lines of the Fingernailson WebMD
{{Eponymous medical signs for integumentary system
Conditions of the skin appendages
Medical signs