Beau’s lines are a type of acquired onychodystrophy as a result of damage to the matrix of the nail plate. It is clinically manifested by transverse lines, the depth of which (up to 1 mm) is proportional to the severity of the pathology. Beau’s lines do not differ in color from a healthy nail, they occur after injuries, against the background of severe infections, cardiovascular diseases, skin pathology. The diagnosis is made by a dermatologist on the basis of clinical manifestations, dermatoscopy is additionally used, scraping from the lesion on mushrooms. Treatment is aimed at restoring the chemical composition of the nail: baths with herbal solutions, electrophoresis with vitamins, paraffin applications, therapeutic mud, UVI.
L60.4 Beau’s Lines
Beau’s lines – pathology of the nail plate in the form of transverse linear depressions that have arisen as a result of damage to the growth zone of the nail. The arc-shaped stripes of Beau-Reilly were first described by the French military surgeon Joseph Honoré Simon Beau in the middle of the nineteenth century, noticing this symptom in many wounded soldiers. He called the cause of such pathology of nails a temporary stop of their growth as a result of injuries and stress. Modern dermatologists believe that transverse lines are nothing but the result of trophic disorders of the nail matrix that change its chemical composition. Taking into account the fact that the nail plate grows completely in about 90 days, by the distance from the nail roller (the point of the beginning of nail growth) to the Bo line, it is possible to determine the time of injury or the prescription of the existence of a chronic pathology that caused nail changes. The pathological process does not have a gender component, although the Beau’s Lines are called manicure onychodystrophy, does not have seasonal and age-related features, is non-endemic.
Beau’s lines are polyethological. The main triggers of the pathological process can be considered uncontrolled medication or the toxic effect of potent drugs (chemotherapy), injuries, hypothermia, metabolic disorders (diets), infections, diseases of the cardiovascular system. The immediate cause of the appearance of Beau’s lines is the oppression of the nail matrix. Metabolic and trophic disorders in the process of contact of pathological antigens with periarticular tissues and corneal cells of the nail plate lead to imbalances in tissue nutrition, changes in the individual genetically programmed chemical composition of the nail.
The matrix of the nail, capable of growth due to the horny cells of the epidermis, is located under the root of the nail and is connected to the periosteum in the distal part. The white half-moon of the nail or lunule marks the border of its growing part. Mechanical damage to the nail in the lunule area leads to a blockade of the natural channels of matrix nutrition, impairs the nutrition of tissues that ensure the growth of the nail plate and guarantee the constancy of the chemical composition of the nail. As a result, mechanical Beau’s lines arise.
Fungal or other infection, the action of toxic or medicinal substances acting as pathogenic triggers indirectly disrupts the trophism of the dermis and its appendages, which also causes a deterioration in the nutrition of the nail bed area. In this case, pathogenic antigens, penetrating into the keratinocytes of the matrix, damage them, cause the production of pro-inflammatory cytokines, which destroy the well-functioning self-regulating metabolism inside the cell, and in the dermis, through a number of biochemical reactions, provoke a blockade of the protein necessary for the construction of the nail.
Deprived of normal nutrition, matrix tissues cease to produce a sufficient number of growth cells, which leads to a change in the chemical composition of the nail plate, nail dystrophy, and its deformation. In other words, in this case, Beau’s lines are the result of spontaneous interruption of normal keratin synthesis in the nail matrix due to a variety of reasons. The degree of severity of pathological changes in the matrix of the nail plate determines the clinical manifestations of Beau’s lines.
Classification and symptoms
In modern dermatology, Beau’s lines are a frequent find in clinical practice. The classification of pathology is purely applied. Boreal furrows are distinguished by the depth of the nail lesion, which is important when prescribing adequate therapy for the pathological process. The surface lines of Beau’s indicate the presence of small metabolic defects, deep ones indicate severe metabolic disorders or serious injuries. There is a classification of Beau’s lines by the number of bands. One furrow makes it possible to predict rapid healing without any medical intervention, several furrows make the nail wavy and are a sign of a chronic pathological process. Taking into account the multiplicity of Beau’s-Reilly bands, it is possible to estimate the frequency of exacerbations and the duration of light intervals between relapses by the rate of nail growth from line to line.
Beau’s lines, in fact, are not lines in the direct sense of the word. Rather, these are temporary depressions in the nail corresponding to the moment of suppression of the growth of horn cells in the matrix under the influence of pathological triggers. The clinical picture of the Beau’s lines is characterized by the appearance of transverse furrows, which necessarily pass through the entire width of the nail from edge to edge between the side rollers and do not exceed 1 mm in depth. Beau’s lines can be localized on the nail plates of both hands and feet.
Beau’s lines that occur against the background of chronic pathologies are able to turn the smooth surface of the nail into a wavy one. However, both with acute trauma and with a chronic pathological process, the type of Beau’s lines can be very different – from arcs, furrows, grooves and channels to classical linear defects. In deep Beau’s lines, there is sometimes a small frill along the posterior (distal) edge, while the color of the nail and its smoothness do not change in intact areas. Beau’s lines may be associated with latent systemic skin pathology, rheumatism, pemphigus, diabetes mellitus, malaria, Raynaud’s disease. Sometimes they are the only clinical sign that precedes a myocardial infarction.
Diagnosis and treatment
The diagnosis is made by a dermatologist based on anamnesis and typical clinical manifestations. In complex cases of diagnosis of Beau’s lines, it may be necessary to consult a podiatrist in order to identify and correct concomitant background pathology. Differentiate Beau’s lines with onychomycosis, nail psoriasis, lichen planus. The standard examination of a patient with Beau’s lines includes dermatoscopy and the mandatory exclusion of fungal nail lesions, for this, a scrape is taken from the lesion and microscopy is performed.
A slight degree of damage to the nail plate does not require treatment, over time the nail grows back, and the lines of the nail disappear without a trace on their own. In severe cases, correction of the underlying disease that caused the development of this pathology is necessary. In addition, during the pathological process, baths with herbal infusions, paraffin applications, ozokerite, therapeutic mud are locally used. Electrophoresis with vitamins, UVI is effective. For the purpose of prevention, a protein diet is indicated, excluding contact with nail polishes. The prognosis depends on the features of the course of the provoking pathology.