Terry's nails is a physical condition in which a person's fingernails or toenails appear white with a characteristic "ground glass" appearance without any lunula. The condition is thought to be due to a decrease in vascularity and an increase in connective tissue within the nail bed. It frequently occurs in the setting of liver failure, cirrhosis, diabetes mellitus, congestive heart failure, hyperthyroidism, or malnutrition. Eighty percent of patients with severe liver disease have Terry's nails, but they are also found in patients with kidney failure, in patients with congestive heart failure and are described as a brown arc near the ends of the nails. The recognition of characteristic nail patterns, such as Terry’s nails, may be a helpful herald for early diagnosis of systemic diseases.

This was named for Dr. Richard Terry.

ICD 10: L60.8

Symptoms of an ingrown nail include pain along the margins of the nail (caused by hypergranulation that occurs around the aforementioned margins), worsening of pain when wearing tight footwear, and sensitivity to pressure of any kind, even the weight of bedsheets. Bumping of an affected toe can produce sharp and even excruciating pain as the tissue is punctured further by the nail. By the very nature of the condition, ingrown nails become easily infected unless special care is taken early to treat the condition by keeping the area clean. Signs of infection include redness and swelling of the area around the nail, drainage of pus and watery discharge tinged with blood. The main symptom is swelling at the base of the nail on the ingrowing side (though it may be both sides).

Onychocryptosis should not be confused with a similar nail disorder, convex nail, nor with other painful conditions such as involuted nails, nor with the presence of small corns, callus or debris down the nail sulci (grooves on either side).

Trachyonychia, sometimes called sandpapered nails, is a condition characterized by rough accentuated linear ridges (longitudinal striations) on the nails of the fingers and toes. When the condition occurs on all the twenty nails of the fingers and toes, it is known as twenty-nail dystrophy, most evident in childhood, favoring males.

Trachyonychia causes the nails to become opalescent, thin, dull, fragile, and finely longitudinally ridged, and, as a result, distally notched. It can be a manifestation of lichen planus, psoriasis, alopecia areata, immunoglobulin A deficiency, atopic dermatitis, and ichthyosis vulgaris.

"The longitudinal striations can occur as a normal part of the aging process", and not until the nails start to thin and get a sandpaper look is the condition called trachonychia. The nails are opalescent and frequently are brittle and split at the free margin. There has been evidence of the condition as a cutaneous manifestation of lichen planus. It has also been associated with other diseases such as eczema, psoriasis, alopecia areata, and atopic dermatitis. Trachonychia is often seen in vitiligo patients – suggesting that they are more susceptible to this condition.

An ingrown nail (also known as onychocryptosis from ὄνυξ ("onyx", "nail") + κρυπτός ("kryptos", "hidden") or unguis incarnates) is a common form of nail disease. It is an often painful condition in which the nail grows so that it cuts into one or both sides of the paronychium or nail bed.

The common opinion is that the nail enters inside the paronychium, but an ingrown toenail can simply be overgrown toe skin. The condition starts from a microbial inflammation of the paronychium, then a granuloma, which results in a nail buried inside of the granuloma. While ingrown nails can occur in the nails of both the hands and the feet , they occur most commonly with the toenails.

A true ingrown toenail is caused by the actual penetration of flesh by a sliver of nail.

Longitudinal leukonychia is far less common and features smaller 1mm white longitudinal lines visible under the nail plate. It may be associated with Darier's disease.

Also known as "true" leukonychia, this is the most common form of leukonychia, in which small white spots appear on the nails. Picking and biting of the nails are a prominent cause in young children and nail biters. Besides parakeratosis, air that is trapped between the cells may also cause this appearance. It is also caused by trauma. In most cases, when white spots appear on a single or a couple of fingers or toes, the most common cause is injury to the base (matrix) of the nail. When this is the case, white spots disappear after around eight months, which is the amount of time necessary for nails to regrow completely. The pattern and number of spots may change as the nail grows.

Hapalonychia, also known as egg-shell nail, is a condition in which the top of a toe or finger nail becomes soft and thin, causing it to bend or break. This condition can manifest as a result of genetic discrepancy and may also occur due to malnutrition and debility. Nails are often a representation of the internal nutritional of health. Although overall well-being is not typically determined by nail health, fissures, breaks and calcium spots are minor indications of inner health. Hapalonychia may also be attributed to myxedema, rheumatoid arthritis, anorexia, bulimia, Hansen's disease, Raynaud phenomenon, oral retinoid therapy, or radiodermatitis.

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. This condition of the nail was named by a French physician, Joseph Honoré Simon Beau (1806–1865), who first described it in 1846.

Beau's lines are horizontal, going across the nail, and should not be confused with vertical ridges going from the bottom (cuticle) 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 of the fingernails. While Beau's lines are actual ridges and indentations in the nail plate, Muehrcke lines are areas of hypopigmentation without palpable ridges; they affect the underlying nail bed, and not the nail itself. Beau's lines should also be distinguished from Mees' lines of the fingernails, which are areas of discoloration in the nail plate.

There are several causes of Beau's lines. It is believed that there is a temporary cessation of cell division in the nail matrix. This may be caused by an infection 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, hypocalcaemia, 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 or malnutrition. Beau's lines can also be seen one to two months after the onset of fever in children with Kawasaki disease.

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 0.1mm/day and toenails at about 0.05mm/day. With this in mind the date of the stress causing Beau's lines and other identifiable marks on nails can be estimated. As the nail grows out, the ridge visibly moves upwards toward the nail edge. When the ridge reaches the nail edge, the fingertips can become quite sore due to the mis-shapen nail pressing into the flesh deeper than usual, exposing the sensitive nail bed (the quick) at the nail edge.

A researcher found Beau's lines in the fingernails of two of six divers following a deep saturation dive to a pressure equal to 305 meters of sea water, and in six of six divers following a similar dive to 335 meters. They have also been seen in Ötzi the Iceman.

Koilonychia (from the Greek: koilos-, "hollow", onikh-, "nail"), also known as spoon nails, is a nail disease that can be a sign of hypochromic anemia, especially iron-deficiency anemia. " It refers to abnormally thin nails (usually of the hand) which have lost their convexity, becoming flat or even concave in shape. In a sense, koilonychia is the opposite of nail clubbing. In early stages nails may be brittle and chip or break

easily.

Koilonychia is associated with Plummer-Vinson syndrome and iron deficiency anemia.

Onychorrhexis (from the Greek words ὄνυχο- "ónycho-", "nail" and ῥῆξις "rhexis", "bursting"), also known as brittle nails, is a brittleness with breakage of finger or toenails that may result from excessive strong soap and water exposure, nail polish remover, hypothyroidism, anemia, anorexia nervosa or bulimia, or after oral retinoid therapy. Onychorrhexis affects up to 20% of the population.

Symptoms include lack of sweat glands, thin hair, brittle nails, mottled skin, and lack of fingerprints.

The skin lesions evolve through characteristic stages:

1. blistering (from birth to about four months of age),

2. a wart-like rash (for several months),

3. swirling macular hyperpigmentation (from about six months of age into adulthood), followed by

4. linear hypopigmentation.

Alopecia, hypodontia, abnormal tooth shape, and dystrophic nails are observed. Some patients have retinal vascular abnormalities predisposing to retinal detachment in early childhood. Cognitive delays/mental retardation are occasionally seen.

Discolored skin is caused by excessive deposits of melanin (normal skin pigment).

Most newborns with IP will develop discolored skin within the first two weeks.

The pigmentation involves the trunk and extremities, is slate-grey, blue or brown, and is distributed in irregular marbled or wavy lines.

The discoloration sometimes fades with age.

Neurological problems can include: cerebral atrophy, the formation of small cavities in the central white matter of the brain, and the loss of neurons in the cerebellar cortex.

About 20% of children with IP will have slow motor development, muscle weakness in one or both sides of the body, mental retardation, and seizures.

They are also likely to have visual problems, which can include: crossed eyes, cataracts, and severe visual loss.

Dental problems are common, and include missing or peg-shaped teeth - patients with IP often keep milk teeth into adult life.

Breast anomalies can occur in 1% of patients; anomalies can include hypoplasia and supernumerary nipples.

Skeletal and structural anomalies can occur in approximately 14% of patients, including:

- Somatic asymmetry,

- Hemivertebrae,

- Scoliosis,

- Spina bifida,

- Syndactyly,

- Acheiria (congenital absence of the hands - note: other limbs may be affected),

- Ear anomalies,

- Extra ribs,

- Skull deformities,

- Primary pulmonary hypertension,

- Cardiopulmonary failure

Dysplastic nails are a cutaneous condition, and may be a subtle finding of ridging, flaking, or poor growth of the nails, or more diffuse with nearly complete loss of nails. This condition may be seen in a number of syndromes, including Dyskeratosis congenita and Nail–patella syndrome.

Onychogryphosis may be caused by trauma or peripheral vascular disease, but most often secondary to self-neglect and failure to cut the nails for extended periods of time. This condition is most commonly seen in the elderly.

Neoplasms of the nailbed may often present with paronychia, ingrown nail, onycholysis, pyogenic granuloma, nail-plate dystrophy, longitudinal erythronychia, bleeding, and discolorations. There are various benign and malignant neoplasms that may occur in or overlying the nail matrix and in the nailbed, and symptoms may include pain, itching, and throbbing.

Benign tumors of the nails include verruca, pyogenic granuloma, fibromas, nevus cell nevi, myxoid cysts, angiofibromas (Koenen tumors), and epidermoid cysts.

Squamous cell carcinoma of the nailbed is uncommon, and often mistaken for a pyogenic granuloma initially. Subungual melanoma is frequently diagnosed late in the course of growth.

Onychogryphosis (also known as onychogryposis or ram's horn nails) is a hypertrophy that may produce nails resembling claws or a ram's horn.

Darier disease affects both men and women and is not contagious. The disease often starts during or later than the teenage years, typically by the third decade. Short stature is common. The symptoms of the disease are thought to be caused by an abnormality in the desmosome-keratin filament complex leading to a breakdown in cell adhesion.

Worldwide prevalence is estimated as between 1: 30,000 and 1: 100,000. Case studies have shown estimated prevalence by country to be 3.8: 100,000 in Slovenia, 1: 36,000 in north-east England, 1: 30,000 in Scotland, and 1: 100,000 in Denmark

It most commonly affects the chest, neck, back, ears, forehead, and groin, but may involve other body areas. The rash associated with Darier's disease often has a distinct odor. Palms & soles may become thickened, intra oral papules can be found. Finger nails become fragile and this helps in diagnosis of the disease. The rash can be aggravated by heat, humidity, and exposure to sunlight. In some cases, sunlight makes it better, especially in the forehead.

Minor forms of the disease are the most common, and may remain undiagnosed throughout life. These consist mainly of minor rashes without odor that are aggravated by heat, humidity, stress and sunlight. Poorly formed fingernails containing vertical striations are diagnostic.

A recent study examined neuropsychiatric conditions in a non-random sample of 100 British individuals assessed as having DAR. There were high lifetime rates for mood disorders (50%), including depression (30%), bipolar disorder (4%), suicidal thoughts (31%) and suicide attempts (13%), suggesting a possible common genetic link. Scattered case studies also suggest a possible link to learning disorders (not yet confirmed).

Hangnails can become infected and cause paronychia, a type of skin infection that occurs around the nails. Treatments for paronychia vary with severity, but may include soaking in hot salty water, the use of oral antibiotic medication, or clinical lancing. Paronychia itself rarely results in further complications but can lead to abscess, permanent changes to the shape of the nail or the spread of infection.

Blue nails, or more formally azure lunula, are characterized by a blue discoloration of the lunulae, seen in argyria and cases of hepatolenticular degeneration (Wilson's disease), also having been reported in hemoglobin M disease and hereditary acrolabial telangiectases.

In Wilson's disease the blue color involves the lunula (most intense pigmentation) and fades proximally. In argyria, the nail is permanently pigmented a slate-blue color and is most evident in the lunula. Minocycline and Zidovudine can also turn the nail plate blue-gray. There are also reports of hydroxyurea as a rare cause.

A hangnail is a small, torn piece of skin, more specifically eponychium or paronychium, next to a fingernail or toenail.

Darier's disease (DAR), also known as Darier disease, Darier–White disease, Dyskeratosis follicularis and Keratosis follicularis, is an autosomal dominant disorder discovered by French dermatologist Ferdinand-Jean Darier. Darier's is characterized by dark crusty patches on the skin, sometimes containing pus. The crusty patches are also known as keratotic papules, keratosis follicularis or dyskeratosis follicularis.

Mild forms of the disease are the most common, consisting solely of skin rashes that flare up under certain conditions such as high humidity, high stress or tight-fitting clothes. Even in mild forms, short stature combined with poorly formed fingernails containing vertical striations are diagnostic.

Mees' lines or Aldrich–Mees' lines, also called leukonychia striata, are white lines of discoloration across the nails of the fingers and toes (leukonychia).

In season 6 of House MD in the episode 12 titled Remorse, House diagnoses his patient with Wilson's Disease in absence of Kayser-Fleischer rings by removing the nail polish to note the blue nails.

They are typically white bands traversing the width of the nail. As the nail grows they move towards the end, and finally disappear when trimmed.

Keratosis Pharyngis is a medical condition where keratin grows on the surface of the pharynx, that is the part of the throat at the back of the mouth. Keratin is a protein that normally occurs as the main constituent of hair and nails.

It is characterized by the presence of whitish-yellow dots on the pharyngeal wall, tonsils or lingual tonsils.

They are firmly adherent and cannot be wiped off.

The surrounding region does not show any sign or inflammation or any other constitutional signs.

The disease usually shows spontaneous regression.

One patient who was diagnosed with Keratosis Pharyngis had white spots on the base of the tongue and on the pharynx, and hurt a little when swallowing. No treatment was found to help, but the condition went away by itself eventually.