Nail Deformities and Dystrophies

In some congenital ectodermal dysplasias, patients have no nails (anonychia). In pachyonychia congenita, the nail beds are thickened, discolored, and transversely hypercurved (pincer nail deformity). Nail-patella syndrome Nail-Patella Syndrome Nail-patella syndrome is a rare inherited disorder of mesenchymal tissue characterized by abnormalities of bones, joints, fingernails and toenails, and kidneys. Diagnosis is clinical. There... read more causes triangular lunulae and partially absent thumb nails. Patients with Darier disease can have nails with red and white streaks and a distal V-shaped nick.

In Plummer-Vinson syndrome Esophageal Web An esophageal web is a thin mucosal membrane that grows across the lumen of the upper esophagus and may cause dysphagia. (See also Overview of Esophageal and Swallowing Disorders.) This image... read more (esophageal webs caused by severe, untreated iron deficiency), 50% of patients have koilonychia (concave, spoon-shaped nails).

Yellow nail syndrome is a rare condition characterized by slow-growing, thickened, hypercurved, yellow nails. This condition typically occurs in patients with lymphedema and/or chronic respiratory disorders. Chronic bronchial infections are present in about half of reported cases.

Half-and-half nails (Lindsay nails) occur usually with renal failure Chronic Kidney Disease Chronic kidney disease (CKD) is long-standing, progressive deterioration of renal function. Symptoms develop slowly and in advanced stages include anorexia, nausea, vomiting, stomatitis, dysgeusia... read more ; the proximal half of the nail is white, and the distal half is pink or red-brown. Half-and-half nails occur in 20 to 50% of patients who have chronic kidney disease; however, this nail abnormality has been reported in various other chronic diseases including Crohn disease, cirrhosis, pellagra, and Kawasaki disease. This abnormality also occurs in healthy people (1 Systemic nail deformities and dystrophies reference Deformities are often considered together with dystrophies, but the two are slightly different; deformities are generally considered to be gross changes in nail shape, whereas dystrophies are... read more ).

Terry nails are characterized by whiteness of about 80% of the nail bed with a 0.5- to 3.0-mm brown-to-pink distal band. Terry nails are often associated with cirrhosis, chronic heart failure, and adult-onset diabetes mellitus. Differentiation from half-and-half nails can be difficult (1 Systemic nail deformities and dystrophies reference Deformities are often considered together with dystrophies, but the two are slightly different; deformities are generally considered to be gross changes in nail shape, whereas dystrophies are... read more ).

White nails occur with cirrhosis Cirrhosis Cirrhosis is a late stage of hepatic fibrosis that has resulted in widespread distortion of normal hepatic architecture. Cirrhosis is characterized by regenerative nodules surrounded by dense... read more , although the distal third may remain pinker. Intensely white nails, also called Terry nails, can be present in patients with chronic liver or kidney failure, heart failure, or diabetes. Terry nails are a type of leukonychia; the abnormality is not in the nail itself but rather the nail bed, causing the nail the appear white. In Terry nails, nearly the entire nail is opaque white and the lunula is not visible. There is a thin zone of normal pink nail bed at the distal edge of the nail. Terry nails may sometimes occur as part of normal aging (1 Systemic nail deformities and dystrophies reference Deformities are often considered together with dystrophies, but the two are slightly different; deformities are generally considered to be gross changes in nail shape, whereas dystrophies are... read more ).

Beau lines are horizontal grooves in the nail plate that occur when nail growth temporarily slows, which can occur after infection, trauma, systemic illness, or during cycles of chemotherapy. Onychomadesis similarly results from temporary growth arrest of the nail matrix and differs from Beau lines in that the full thickness of the nail is involved, causing a proximal separation of the nail plate from the nail bed. Onychomadesis most frequently occurs several months after hand-foot-and-mouth disease Hand-Foot-and-Mouth Disease (HFMD) Hand-foot-and-mouth disease (HFMD) is a febrile disorder usually caused by coxsackievirus A16, enterovirus 71, or other enteroviruses. Infection causes a vesicular eruption on the hands, feet... read more but can occur after other viral infections. Nails affected by Beau lines or onychomadesis regrow normally with time.

In psoriasis Psoriasis Psoriasis is an inflammatory disease that manifests most commonly as well-circumscribed, erythematous papules and plaques covered with silvery scales. Multiple factors contribute, including... read more , nails may have a number of changes, including irregular pits, oil spots (localized areas of tan-brown discoloration), separation of part of the nail from the nail bed (onycholysis Onycholysis Deformities are often considered together with dystrophies, but the two are slightly different; deformities are generally considered to be gross changes in nail shape, whereas dystrophies are... read more ), and thickening and crumbling of the nail plate. Nail psoriasis is independently associated with treatment-resistant psoriatic disease and is a risk factor for development of psoriatic arthritis Psoriatic Arthritis Psoriatic arthritis is a seronegative spondyloarthropathy and chronic inflammatory arthritis that occurs in people with psoriasis of the skin or nails. The arthritis is often asymmetric, and... read more . Treatment of nail psoriasis is challenging, but immunomodulatory agents are the most effective (1 Dermatologic nail deformities references Deformities are often considered together with dystrophies, but the two are slightly different; deformities are generally considered to be gross changes in nail shape, whereas dystrophies are... read more , 2 Dermatologic nail deformities references Deformities are often considered together with dystrophies, but the two are slightly different; deformities are generally considered to be gross changes in nail shape, whereas dystrophies are... read more ). Topical therapies can lead to modest improvement. Device-based therapies (eg, laser, light) need more study to judge their effectiveness.

Lichen planus Lichen Planus Lichen planus is a recurrent, pruritic, inflammatory eruption characterized by small, discrete, polygonal, flat-topped, violaceous papules that may coalesce into rough scaly plaques, often accompanied... read more of the nail matrix initially causes potentially reversible nail changes, including longitudinal ridging, fissuring, erythema of the lunula, and distal splitting of the nail. Over time, scarring and irreversible changes may occur, including nail atrophy, pterygium formation, and total nail loss. Lichen planus of the nail unit requires management early in the disease to prevent permanent disfigurement. Treatment options include topical, intralesional, and systemic corticosteroids. However, relapse may occur after therapy in some patients. Pterygium of the nail, which is caused by lichen planus, is characterized by scarring from the proximal nail outward in a V formation, which leads ultimately to nail loss.

Alopecia areata Alopecia Areata Alopecia areata is typically sudden patchy nonscarring hair loss in people with no obvious skin or systemic disorder. Diagnosis is typically by inspection, although sometimes a skin biopsy is... read more can be accompanied by regular pits that form a geometric pattern. Pits are small and fine. Alopecia areata may also be associated with severe onychorrhexis (brittleness with nail breakage). Treatment options include intralesional and topical corticosteroids and topical sensitizers such as squaric acid dibutylester. Newer therapies including tofacitinib and apremilast have shown some promise.

Cancer chemotherapy drugs (especially the taxanes) can cause melanonychia (nail plate pigmentation), which can be diffuse or may occur in transverse bands. Some drugs can cause characteristic changes in nail coloration:

Tobacco smoking or nail polish can result in yellow or brownish discoloration of nails and fingertips.

White transverse lines of the nails (Mees lines) may occur with chemotherapy, acute arsenic intoxication, malignant tumors, myocardial infarction, thallium and antimony intoxication, fluorosis, and even during etretinate therapy. These lines are not due to changes in the nail bed, but are a true leukonychia, and the nails can grow out normally if the insulting exposure has been removed. Mees lines also develop with trauma to the finger, although traumatic white lines usually do not span the entire nail.

The fungus Trichophyton mentagrophytes causes a chalky white discoloration of the surface of the nail plate.

Green-nail syndrome is caused by infection with Pseudomonas. It is generally a harmless infection, usually of 1 or 2 nails, and is noteworthy for its striking blue-green color. It often occurs in patients with onycholysis Onycholysis Deformities are often considered together with dystrophies, but the two are slightly different; deformities are generally considered to be gross changes in nail shape, whereas dystrophies are... read more or chronic paronychia Chronic Paronychia Chronic paronychia is recurrent or persistent nail fold inflammation, typically of the fingers. (See also Overview of Nail Disorders.) Chronic paronychia is an inflammatory disorder of the nail... read more whose nails have been exposed to irritants or have had excessive exposure to water. If the onycholysis or chronic paronychia is treated effectively, the Pseudomonas infection will resolve. Alternatively, topical gentamycin ointment can be effective in chronic cases. Patients should avoid irritants and excess moisture. Frequent clipping of the nail increases the response to treatment.

Median nail dystrophy is characterized by small cracks in the nail that extend laterally and look like the branches of an evergreen tree (eg, fir tree, such as a Christmas tree). The cracks and ridges are similar to those seen in habit-tic nail deformity (which is dystrophy of the central nail caused by repetitive trauma to the nail matrix resulting from rubbing or picking with another finger). The cause of median nail dystrophy is unknown in some cases, but trauma is thought to play a role. Frequent use of personal digital devices that subject the nails to repetitive striking has been implicated in several cases. Tacrolimus 0.1% at bedtime without occlusion has been successful when patients stop all activities that might lead to repetitive low-level trauma.

Melanonychia striata are hyperpigmented bands that are longitudinal and extend from the proximal nail fold and cuticle to the free distal end of the nail plate. Pigmentation results from deposition of melanin by melanocytes in the nail matrix. Deposition of melanin is increased by melanocyte activation (increased production of melanin in the nail cells) or by melanocytic hyperplasia (increased production of melanocytes in the nail matrix).

Melanocyte activation may be a normal physiologic variant in people with darker skin. This variant, often called ethnic melanonychia, requires no treatment. Other causes of melanocyte activation include trauma, pregnancy, Addison disease and other endocrine disorders, infections, postinflammatory hyperpigmentation, and the use of certain drugs, including doxorubicin, 5-fluorouracil, zidovudine, and psoralens.

Melanocytic hyperplasia can be caused by benign conditions, such as nail matrix melanocytic nevus or nail lentigo, or by malignant melanoma. Factors more often associated with malignant melanoma of the nail matrix include new onset after middle age, presence of pigmentation on the dominant thumb or hallux, rapid growth or darkening, bandwidth > 3 mm, associated nail plate dystrophy, or Hutchinson sign (extension of hyperpigmentation onto the proximal and/or lateral nail fold). Rapid biopsy and treatment are essential in cases of suspected melanoma Treatment Malignant melanoma arises from melanocytes in a pigmented area (eg, skin, mucous membranes, eyes, or central nervous system). Metastasis is correlated with depth of dermal invasion. With spread... read more (1 Melanonychia striata reference Deformities are often considered together with dystrophies, but the two are slightly different; deformities are generally considered to be gross changes in nail shape, whereas dystrophies are... read more ).

Onycholysis is separation of the nail plate from the nail bed or complete nail plate loss. It can occur as a drug reaction in patients treated with tetracyclines (photo-onycholysis), doxorubicin, 5-fluorouracil, cardiovascular drugs (particularly practolol and captopril), cloxacillin and cephaloridine (rarely), trimethoprim/sulfamethoxazole, diflunisal, etretinate, indomethacin, isoniazid, griseofulvin, and isotretinoin. Simple (ie, not associated with another nail or skin disorder) onycholysis may also result from exposure to irritants, such as frequent exposure to water, citrus fruits, or chemicals. Irritant contact dermatitis Irritant contact dermatitis (ICD) Contact dermatitis is inflammation of the skin caused by direct contact with irritants (irritant contact dermatitis) or allergens (allergic contact dermatitis). Symptoms include pruritus and... read more of the hands and fingers may lead to onycholysis (1 Onycholysis reference Deformities are often considered together with dystrophies, but the two are slightly different; deformities are generally considered to be gross changes in nail shape, whereas dystrophies are... read more ). Colonization of the nail bed with Candida albicans may occur, but treating the underlying irritant exposure leads to resolution of the onycholysis, with or without treating the Candida.

Partial onycholysis may also occur in patients with psoriasis Psoriasis Psoriasis is an inflammatory disease that manifests most commonly as well-circumscribed, erythematous papules and plaques covered with silvery scales. Multiple factors contribute, including... read more or thyrotoxicosis Hyperthyroidism Hyperthyroidism is characterized by hypermetabolism and elevated serum levels of free thyroid hormones. Symptoms include palpitations, fatigue, weight loss, heat intolerance, anxiety, and tremor... read more .

Pincer nail deformity is a transverse over-curvature of the nail plate. It is most often caused by onychomycosis Onychomycosis Onychomycosis is fungal infection of the nail plate, nail bed, or both. The nails typically are deformed and discolored white or yellow. Diagnosis is by appearance, wet mount, culture, polymerase... read more , psoriasis Psoriasis Psoriasis is an inflammatory disease that manifests most commonly as well-circumscribed, erythematous papules and plaques covered with silvery scales. Multiple factors contribute, including... read more , tumors of the nail apparatus, and poorly fitting shoes. It has also been reported in patients with systemic lupus erythematosus Systemic Lupus Erythematosus (SLE) Systemic lupus erythematosus is a chronic, multisystem, inflammatory disorder of autoimmune etiology, occurring predominantly in young women. Common manifestations may include arthralgias and... read more , Kawasaki disease Kawasaki Disease Kawasaki disease is a vasculitis, sometimes involving the coronary arteries, that tends to occur in infants and children between the ages of 1 year and 8 years. It is characterized by prolonged... read more , end-stage renal disease Chronic Kidney Disease Chronic kidney disease (CKD) is long-standing, progressive deterioration of renal function. Symptoms develop slowly and in advanced stages include anorexia, nausea, vomiting, stomatitis, dysgeusia... read more , and some genetic syndromes (eg, paronychia congenita). Patients often have pain at the borders of the nail where the nail plate curves into the tips of the fingers or toes. There is no established treatment of choice, but a number of surgical techniques have been successful (1 Pincer nail deformity references Deformities are often considered together with dystrophies, but the two are slightly different; deformities are generally considered to be gross changes in nail shape, whereas dystrophies are... read more , 2 Pincer nail deformity references Deformities are often considered together with dystrophies, but the two are slightly different; deformities are generally considered to be gross changes in nail shape, whereas dystrophies are... read more , 3 Pincer nail deformity references Deformities are often considered together with dystrophies, but the two are slightly different; deformities are generally considered to be gross changes in nail shape, whereas dystrophies are... read more ).

Trachyonychia (rough, opaque nails) may occur with alopecia areata Alopecia Areata Alopecia areata is typically sudden patchy nonscarring hair loss in people with no obvious skin or systemic disorder. Diagnosis is typically by inspection, although sometimes a skin biopsy is... read more , lichen planus Lichen Planus Lichen planus is a recurrent, pruritic, inflammatory eruption characterized by small, discrete, polygonal, flat-topped, violaceous papules that may coalesce into rough scaly plaques, often accompanied... read more , atopic dermatitis Atopic Dermatitis (Eczema) Atopic dermatitis is a chronic relapsing inflammatory skin disorder with a complex pathogenesis involving genetic susceptibility, immunologic and epidermal barrier dysfunction, and environmental... read more , and psoriasis Psoriasis Psoriasis is an inflammatory disease that manifests most commonly as well-circumscribed, erythematous papules and plaques covered with silvery scales. Multiple factors contribute, including... read more . It is most common among children. When present in all nails, trachyonychia is often called 20-nail dystrophy. When it occurs in children, it tends to resolve spontaneously. When it occurs in adults, treatment is aimed at the underlying disorder.

Benign and malignant tumors can affect the nail unit, causing deformity. Benign tumors include myxoid cysts, pyogenic granulomas Pyogenic Granulomas Pyogenic granulomas are fleshy, moist or crusty, usually scarlet vascular nodules composed of proliferating capillaries in an edematous stroma. The lesion, composed of vascular tissue, is neither... read more , and glomus tumors. Malignant tumors include Bowen disease Bowen Disease Bowen disease is a superficial squamous cell carcinoma in situ. Diagnosis is by biopsy. Treatment depends on the tumor’s characteristics and may involve curettage and electrodesiccation, surgical... read more , squamous cell carcinoma Squamous Cell Carcinoma Squamous cell carcinoma is a malignant tumor of epidermal keratinocytes that invades the dermis; this cancer usually occurs in sun-exposed areas. Local destruction may be extensive, and metastases... read more , and malignant melanoma Melanoma Malignant melanoma arises from melanocytes in a pigmented area (eg, skin, mucous membranes, eyes, or central nervous system). Metastasis is correlated with depth of dermal invasion. With spread... read more . When cancer is suspected, expeditious biopsy followed by referral to a surgeon is strongly advised.