Muehrcke's nails or Muehrcke's lines ( apparent leukonychia striata) are changes in the

fingernail A nail is a protective plate characteristically found at the tip of the digits (fingers and toes) of all primates, corresponding to the claws in other tetrapod animals. Fingernails and toenails are made of a tough rigid protein called alpha-k ...

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, they are not grooved (no 3-dimensional deformity), and in contrast to Mees' lines, 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 concentration, level of human serum albumin, albumin in the blood is low. This can be due to decreased production in the liver, increased loss in the gastrointestinal tract or ki ...

, 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 (formerly Terry's of York) is a British chocolate and confectionery brand. The original company was founded in 1767 in York, England, and was part of the city's famous confectionery triumvirate along with Rowntree's and Cravens. The co ...

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 Specific may refer to: * Specificity (disambiguation) * Specific, a cure or therapy for a specific illness Law * Specific deterrence, focussed on an individual * Specific finding, intermediate verdict used by a jury in determining the final ...

with marked

(serum albumin ≤ 2.2 g/dL) indicating decreased protein synthesis, which may occur during periods of metabolic stress (e.g. systemic infection, trauma,

AIDS The HIV, human immunodeficiency virus (HIV) is a retrovirus that attacks the immune system. Without treatment, it can lead to a spectrum of conditions including acquired immunodeficiency syndrome (AIDS). It is a Preventive healthcare, pr ...

chemotherapy Chemotherapy (often abbreviated chemo, sometimes CTX and CTx) is the type of cancer treatment that uses one or more anti-cancer drugs (list of chemotherapeutic agents, chemotherapeutic agents or alkylating agents) in a standard chemotherapy re ...

), or in hypoalbuminemic states such as the

nephrotic syndrome Nephrotic syndrome is a collection of symptoms due to kidney damage. This includes proteinuria, protein in the urine, hypoalbuminemia, low blood albumin levels, hyperlipidemia, high blood lipids, and significant edema, swelling. Other symptoms ...

or dietary protein deficiency. They are also seen in people with end-stage kidney disease on

hemodialysis Hemodialysis, American and British English spelling differences#ae and oe, also spelled haemodialysis, or simply ''"'dialysis'"'', is a process of filtering the blood of a person whose kidneys are not working normally. This type of Kidney dialys ...

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 lymph nodes. The condition was named a ...

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 friction and radiation are typically affected first. Over tim ...

, and

sickle cell anaemia Sickle cell disease (SCD), also simply called sickle cell, is a group of inherited haemoglobin-related blood disorders. The most common type is known as sickle cell anemia. Sickle cell anemia results in an abnormality in the oxygen-carrying ...

. 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 (), known locally as Sagarmatha in Nepal and Qomolangma in Tibet, is Earth's highest mountain above sea level. It lies in the Mahalangur Himal sub-range of the Himalayas and marks part of the China–Nepal border at it ...

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 fortnightly peer-reviewed medical journal, published by BMJ Publishing Group Ltd, which in turn is wholly-owned by the British Medical Association (BMA). ''The BMJ'' has editorial freedom from the BMA. It is one of the world' ...

, 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.

References

Bibliography

* *James, William; Berger, Timothy; Elston, Dirk (2005). ''Andrews' Diseases of the Skin: Clinical Dermatology''. (10th ed.). Saunders. . *
Muehrcke's Lines of the Fingernails
on WebMD {{Eponymous medical signs for integumentary system Conditions of the skin appendages Medical signs Anatomy named for one who described it Nails (anatomy)

Physiology

History

See also

References

Bibliography