Nails As Indicators of Health Status
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Nails as Indicators of Health Status Dr Linda Mayer and Prof R. Bhikha November 2014 Overview The significance of nails as indicators of health status has been recognised as early as the 5th century B.C. when Hippocrates first described clubbing as a symptom of disease. Nails are often referred to as the barometer of overall health. Everything one sees on the outside of the body is a reflection of something going on inside. The colour, texture and shape of the nails reflect the general health of an individual, which may signify underlying systemic diseases. Trauma to the nails should always first be excluded, as well as a thorough physical examination to substantiate any health concerns. However, not every change in the colour or texture of the nails indicates a systemic disease. Old age causes nails to become drier, more brittle and less flexible, due to its loss of moisture and suppleness; damage to the nail changes the colour to purple/black; certain drugs and chemotherapy agents may also alter the colour of the nails, and heredity may also be a factor to consider. Between the keratin layers are fat molecules and water, which give nails their pliability and shiny appearance. Nails which are too soft are more easily damaged and stained and are at risk of peeling or becoming pitted. Frequent exposure to water exposes the nail to becoming infected. Nail plates that become too flexible will lose their strength, whereas nail plates which are too hard will lose their flexibility. The strength of the nails must be balanced with flexibility. The growth of the nails is also an indicator of health status, which is dependent on many factors, including illness, stress, age and biting or improper cutting. The average fingernail growth is 3 mm per month, or about 0, 1 mm per day, which requires about 6 months for complete re-growth, thereby visually portraying the health of a person over this period of time. Toenails take about 12-18 months to regrow, which is two to three times as long as fingernails. The Tibb perspective of nails as an indicator of health status considers the qualities of heat, moisture, coldness and dryness, as well as the individual temperament in determining the predisposition to certain conditions. General lifestyle factors, especially concerning diet and stress, play significant roles in determining the health status of an individual. Food intolerances and nutritional deficiencies, such as a depletion of sulphur in the amino acids, interfere with the binding of keratin, which is responsible for the hard covering of the nail. Emotional stress not only can result in the nails becoming brittle and developing ridges, it also impacts on all other areas of the body. Adequate water intake, exercise, stress reduction, sleep, fresh air and elimination of waste products from the body and retention of valuable nutrients all contribute to health and wellbeing. A healthy and well balanced diet should contain the necessary vitamins and minerals to sustain a healthy mind and body. Anatomical Structures of the Nail. (2) Nails, together with hair, sebaceous and sweat glands are considered to be appendages of the skin. Nails are part of the epidermis, the outer layer of the skin, and are composed of very small cells, called onychocytes, which are mainly made up of keratin, which is a fibrous protein. Nails are very absorbent; ten times more absorbent than skin.1 The nail bed is part of the nail matrix, and is situated from the edge of the germinal matrix, or lanula, to the hyponychium. It contains blood vessels, nerves, and melanin-producing cells. The nail plate is the hard cover of the nail, called keratin, which is situated on the dorsal aspect of the distal phalanx. The keratin is dead cells (also makes up hair and skin) which are produced by the lanula. The nail plate takes on the colour corresponding to the underlying vascular nail bed, and it receives its vascularity from the ulnar and radial digital arteries. The nail plate has many layers which arise from the germinal matrix epithelium (root) of the nail bed. The matrix contains blood vessels, nerves and lymph. The lateral nail fold, or perionychium, is the epidermis which overlies the sides of the nail plate. It is the site of hangnails, ingrown nails, and an infection of the skin called paronychia. The cuticle, or eponychium, is the dead skin at the base of the fingernail or toenail, and is situated between the skin of the finger and the nail plate fusing these structures together and providing a waterproof barrier. The hyponychium is the bed of soft tissue just under the nail at the distal end of the finger, also known as the ʻquickʼ, which acts as a waterproof barrier to reduce the risk of infection, and is rich in white blood cells. The lanula is the white semicircle (half-moon) of the proximal part of the nail plate, where the matrix extends just beyond the nail fold. This half-moon appearance is due to the nail bed being so tightly packed with keratin, that the capillaries (where the blood flows through) are masked by the amount of keratin. When the lanula is not present, this may indicate an underactive thyroid; however, an overlarge lanula may indicate an over-active thyroid.2 The Tibb Perspective From a Tibb perspective, the predisposition for certain conditions and status of the hydration of the nails is reflected by the temperament of an individual and its respective qualities of heat, moisture, coldness and dryness. The Melancholic and Bilious temperaments have the predisposition to have dry skin and hence dry and brittle nails because of their overall dry qualities; whereas the Sanguinous and Phlegmatic temperaments are more prone to moist skin and softer nails due to their overall moist qualities. A balance of these qualities is necessary to prevent nails from becoming too dry or too soft, which can be achieved through lifestyle factors, especially a diet rich in the essential minerals and vitamins, which must be properly absorbed and assimilated by the body. The Melancholic temperament is prone to conditions related to an increase in cold and dryness, such as brittle nails, which break easily due to lack of moisture and keratin. Keratin is derived from the Greek word, Kepas, meaning horn. The keratin is made up of protein, which is the major structural component making up the nails, hair and epidermal layer of the skin. In Tibb protein has an overall quality of dryness, with degrees of heat or coldness and the least amount of moistness. Thickening of the nails can also occur from psoriasis and dry eczema, which have qualities of coldness with dryness. The Sanguinous temperament has qualities of heat and moisture, which, when in the correct proportion and quantity, has a balanced interaction of heat and moisture, which is necessary for the healthy growth of nails. The Bilious temperament is also prone to hard and brittle nails because of the predominance of heat and dryness; whereas the Phlegmatic temperament is prone to nails which may become too soft, due to the predominance of cold and moist qualities. Nail Examination Examination of the nails will not only reveal the overall vitality of the body and underlying pathology, it will also indicate the inner emotional state of the person, as well as occupation, hobbies, and nutritional status.3 All the fingernails and toenails must be examined, together with the skin, mucosa and the rest of the body, as any systemic disorders will reflect the overall health of the nails as well as the body itself. The capillary refill test as well as the Schamroth sign are standardised tests to exclude vascular changes and clubbing respectively. Blood tests or any other tests may have to be performed if systemic disorders or infections are suspected. Any obvious trauma or injuries must first be excluded. Nails should be examined under natural light and without any protective shields, such as nail polish or nail extensions. Transillumination, using a pen torch placed against the pulp of the finger, helps in pointing out the abnormalities in the nail plate.4 The hands must be placed on a surface, which is comfortable to the client so that he/she is relaxed. There must not be any pressure on the hands, as this could alter the vasculature of the nail bed, thereby changing the appearance of the nails. All the nails are examined to include all the anatomical structures, nail colour, textures, shape, thickness or thinness, separation from the nail plate, nail patterns, how many nails affected, as well as establishing nail growth. The surrounding skin is also examined for any changes in skin texture, namely dryness, heat, moisture and any coldness, as well as any bleeding around the nails or signs of inflammation (red, hot swollen, or any pain). History taking will include any trauma, recent severe illness, familiar nail disorders, medical background and the use of drugs. Occupational hazards will include people who work with their hands in water, or who work with hazardous materials and poisons. Each fingernail and toenail is examined individually, and a comparative review is done according to the norm. Fingernails should be pink, with a slight sheen, warm, slightly pliable, with no cracks or ingrown nails. The skin around the nails should be slightly warm and moist, but not too dry. Nails should bend slightly when downward pressure is applied to the free edge, which indicates a balance of heat and moisture in the body. Nail Tests Nail tests include the capillary refill test (blanching), and the Schamroth sign, for clubbing.