Beau's lines are deep grooved lines that run from side to side on 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. ...

or the toenail. They may look like indentations or ridges in the

nail plate 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. ...

.Freedberg, et al. (2003). ''Fitzpatrick's Dermatology in General Medicine''. (6th ed.). McGraw-Hill. . This condition of the nail was named by a French physician, Joseph Honoré Simon Beau (1806–1865), who first described it in 1846.

Signs and symptoms

Beau's lines are horizontal, going across the nailline, and should not be confused with vertical ridges going from the bottom (

cuticle A cuticle (), or cuticula, is any of a variety of tough but flexible, non-mineral outer coverings of an organism, or parts of an organism, that provide protection. Various types of "cuticle" are non- homologous, differing in their origin, structu ...

) of the nail out to the fingertip. These vertical lines are usually a natural consequence of aging and are harmless. Beau's lines should also be distinguished from

Muehrcke's lines Muehrcke's nails or Muehrcke's lines ( apparent leukonychia striata) 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 th ...

of the fingernails. While Beau's lines are actual ridges and indentations in the nail plate, Muehrcke lines are areas of

hypopigmentation Hypopigmentation is characterized specifically as an area of skin becoming lighter than the baseline skin color, but not completely devoid of pigment. This is not to be confused with depigmentation, which is characterized as the absence of all pi ...

without

palpable Palpation is the process of using one's hands to check the body, especially while perceiving/diagnosing a disease or illness. Usually performed by a health care practitioner, it is the process of feeling an object in or on the body to determine ...

ridges; they affect the underlying nail bed, and not the nail itself. Beau's lines should also be distinguished from

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 ...

of the fingernails, which are areas of discoloration in the nail plate. As the nail grows out, the ridge in the nail can be seen to move upwards until it reaches the fingertip. When it reaches this point the fingertips can become sore for a few days due to the nail bed being exposed by the mis-shapen nail.

Causes

There are several causes of Beau's lines. It is believed that there is a temporary cessation of

cell division Cell division is the process by which a parent cell (biology), cell divides into two daughter cells. Cell division usually occurs as part of a larger cell cycle in which the cell grows and replicates its chromosome(s) before dividing. In eukar ...

in the

nail matrix 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 ...

. This may be caused by an

infection An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable dise ...

or problem in the nail fold, where the nail begins to form, or it may be caused by an injury to that area. Some other reasons for these lines include trauma,

coronary occlusion A coronary occlusion is the partial or complete obstruction of blood flow in a coronary artery. This condition may cause a heart attack. In some patients coronary occlusion causes only mild pain, tightness or vague discomfort which may be ignored ...

hypocalcaemia Hypocalcemia is a medical condition characterized by low calcium levels in the blood serum. The normal range of blood calcium is typically between 2.1–2.6 mmol/L (8.8–10.7 mg/dL, 4.3–5.2 mEq/L) while levels less than 2.1 mmol ...

, and skin disease. They may be a sign of systemic disease, or may also be caused by an illness of the body, as well as drugs used in

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

malnutrition Malnutrition occurs when an organism gets too few or too many nutrients, resulting in health problems. Specifically, it is "a deficiency, excess, or imbalance of energy, protein and other nutrients" which adversely affects the body's tissues a ...

. Beau's lines can also be seen one to two months after the onset of fever in children with

Kawasaki disease Kawasaki disease is a syndrome of unknown cause that results in a fever and mainly affects children under 5 years of age. It is a form of vasculitis, where blood vessels become inflamed throughout the body. The fever typically lasts for more tha ...

. Conditions also associated with Beau's lines include uncontrolled diabetes and peripheral vascular disease, as well as illnesses associated with a high fever, such as scarlet fever, measles, mumps and pneumonia. Beau's lines can also be a sign of zinc deficiency.

A researcher found Beau's lines in the fingernails of two of six divers following a deep saturation dive to a pressure equal to of sea water, and in six of six divers following a similar dive to . They have also been seen in

Ötzi the Iceman Ötzi, also called the Iceman, is the natural mummy of a man who lived some time between 3350 and 3105 BC, discovered in September 1991 in the Ötztal Alps (hence the nickname "Ötzi") on the border between Austria and Italy. Ötzi is believed to ...

. Human nails grow at a rate which varies with many factors: age, and the finger or toe in question as well as nutrition. However, typically in healthy populations fingernails grow at about 0.1 mm/day and toenails at about 0.05 mm/day.

References

External links

Image of Beau's Lines from docetaxel chemotherapy
{{Disorders of skin appendages Conditions of the skin appendages Medical signs

Signs and symptoms

Causes

See also

References

External links