Nail dystrophy - an overview (2023)

Dystrophic nails (onychogryposis, onychomycosis)

Deformed nails in elderly and diabetic patients can be difficult to manage at best and catastrophic at worst, especially when accompanied by an insensitive foot. It is recommended to have a small double action rongeur and a nail splitter in the office. These nails can be repositioned quickly and safely with these instruments (Abb. 88.3).

Aside from reducing nail mass, onychomycosis, or fungal infection of the nails, can often be treated with benign neglect since its main effect is cosmetic. If treatment to eradicate the fungal infection is desired, referral to a dermatologist for confirmatory testing by appropriate cultures, followed by inexpensive medical treatment, either by topical or oral agents, may be warranted. Most treatment regimens are prolonged, since it is difficult for various drugs to penetrate the nail. Many of the oral medications have serious side effects and patients should be monitored appropriately for these side effects.

The effectiveness of laser therapy for onychomycosis remains controversial. Lasers are approved by the U.S. Food and Drug Administration (FDA) for the "temporary increase in clear nails in patients with onychomycosis," but laser treatment has resulted in lower cure rates than oral and topical therapies. Therefore, laser treatment is not considered a first-line treatment for onychomycosis.

nail dystrophy

nail dystrophy(Distortion and discoloration of normal nail plate structure) can result from a traumatic or inflammatory process affecting the nail matrix, nail bed, or surrounding tissues. Although onychomycosis, the result of a dermatophyte fungal infection, is the most common cause of nail dystrophy in adults, it is uncommon in prepubertal children (Abb. 8.56). Dystrophic nails often occur as a complication of trauma (Abb. 8.57) or underlying dermatoses such as psoriasis, atopic dermatitis, and lichen planus (Abb. 8.58–8.61).

Nail trauma can cause a subungual hematoma, resulting in a brown-black discoloration. This is especially likely after crush injuries. Diagnosis is usually easy unless the trauma is subtle. Although most hematomas go away without treatment, large, painful collections of blood can be drained by piercing a small hole in the nail plate with a sterile, large-bore needle. This relieves pain and reduces the risk of infection. Dark pigmentation at the base of the big toenail caused by snagging the toe into the end of the shoe during a sudden stop is called "turf toe" and also results from subungual hemorrhage (Abb. 8.62). This must be of melanoma and melanonychia (Abb. 8.63). Hemorrhage can be identified by the presence of purplish-brown pigment in the distal nail and normal proximal nail outgrowth. In melanonychia, gray-brown pigment streaks of variable width extend longitudinally from the proximal nail fold of one or more nails. Although this finding is common in darkly pigmented individuals, it can occur in individuals of any race and age. Irregular or changing streaks of pigment may require a nail biopsy to confirm innocence and rule out melanoma.

Nail biting, grooming, and chronic manipulation of any kind can also lead to nail dystrophy. Repeated trauma to the cuticle can result in leukonychia (transverse white lines) and median nail dystrophy (central longitudinal ridges;Abb. 8.64).

Twenty-nail dystrophy (trachyonychia) is a disorder of otherwise healthy school-age children and is characterized by yellowing, pitting, increased brittleness, and other dystrophic changes that progress over 6 to 18 months and affect most or all nails bearing them to give a roughened texture (Abb. 8.65). Although the course is variable, in many cases the dystrophy heals without scarring over a period of several years. This disorder likely includes a number of conditions that cannot be distinguished unless other skin findings are present.

Nail dystrophy can accompany other skin diseases and help in their diagnosis. For example, alopecia areata is associated with the characteristic Scotch plaid nail pitting (Abb. 8.66). Psoriasis in the nail matrix results in scattered pits that are larger, deeper, and fewer in number than those in alopecia areata (cfAbb. 8.58a). Psoriasis of the nail bed, particularly under the distal nail, causes detachment of the nail plate from the underlying skin (onycholysis) and an oily drop-like discoloration with accumulated scaling (see FigAbb. 8.58b). Onycholysis alone, without pitting or discoloration, can be caused by trauma, infection, nail polish hardener, or phototoxic reactions to drugs like tetracycline (Abb. 8.67).

Trachyonychie (20-Nagel-Dystrophie)

Trachyonychia is characterized by longitudinal ridges, pitting, brittleness, thinning, distal notching, and opalescent discoloration of all nails (Abb. 683.9). Patients must not have associated skin or systemic diseases or other ectodermal defects. Its occasional association with alopecia areata has led some authorities to believe that trachyonychia may reflect an abnormal immunological response to the nail matrix, whereas histopathological studies suggest that it is a manifestation of lichen planus, psoriasis, or spongiotic (eczematous) inflammation of the nail Nagels could act nail matrix. The disorder must be differentiated from fungal infections, psoriasis, nail changes and alopecia areatanail dystrophysecondary to eczema. Eczema and fungal infections rarely cause changes to all nails at the same time. The disease is self-limiting, can be treated with potent topical steroids or topical retinoids, and eventually resolves in adulthood.

nail dystrophy

nail dystrophy(Distortion and discoloration of normal nail plate structure) can result from any traumatic or inflammatory process affecting the nail matrix, nail bed, or surrounding tissues. Although onychomycosis, the result of a dermatophyte fungal infection, is the most common cause of nail dystrophy in adults, it is uncommon in prepubertal children (Abb. 8.56). Dystrophic nails often occur as a complication of trauma (Abb.8.57) or underlying dermatoses such as psoriasis, atopic dermatitis, lichen planus and alopecia areata (figs 8:58-8:61).

Nail trauma can cause a subungual hematoma, resulting in a brown-black discoloration. This is especially likely after crush injuries. Diagnosis is usually easy unless the trauma is subtle. Although most hematomas go away without treatment, large, painful collections of blood can be drained by piercing a small hole in the nail plate with a sterile, large-bore needle. This relieves pain and reduces the risk of infection. Dark pigmentation at the base of the big toenail caused by snagging the toe into the end of the shoe during a sudden stop is called a "turf toe" and also results from subungual hemorrhage (Abb.8.62). This must be of melanoma and melanonychia (Abb. 8.63). Hemorrhage can be identified by the presence of purplish-brown pigment in the distal nail and normal proximal nail outgrowth. In melanonychia, gray-brown pigment streaks of variable width extend longitudinally from the proximal nail fold of one or more nails. Although this finding is common in darkly pigmented individuals, it can occur in individuals of any race and age. Irregular or changing pigment streaks require a nail biopsy to confirm their innocence and rule out melanoma. The extension of a dark longitudinal stripe to the proximal nail fold is called Hutchinson's sign and strongly suggests melanoma.

Nail biting, grooming, and chronic manipulation of any kind can also lead to nail dystrophy. Repeated trauma to the cuticle can produce leukonychia (white transverse lines), and constant plucking of the nail plate leads to median nail dystrophy (median longitudinal ridges;Abb. 8.64).

Twenty-nail dystrophy (trachyonychia) is a disorder of otherwise healthy school-age children and is characterized by yellowing, pitting, increased brittleness, and other dystrophic changes that progress over several months and affect most or all nails, causing them to become rough texture (Abb. 8.65). Although the course is variable, in many cases the dystrophy isdissolves without scarring over a period of several years. This disorder likely includes a number of conditions that cannot be distinguished unless other skin findings are present. The main causes of trachyonychia are lichen planus, alopecia areata and psoriasis.

Nail dystrophy can accompany other skin diseases and help in their diagnosis. For example, alopecia areata is associated with the characteristic Scotch plaid nail pitting (Abb. 8.66). Psoriasis in the nail matrix results in scattered pits that are larger, deeper, and less numerous and more randomly located than in alopecia areata (Abb.8.58a). Psoriasis of the nail bed, particularly under the distal nail, causes detachment of the nail plate from the underlying skin (onycholysis) and an oily drop-like discoloration with aggregate scales (Abb. 8.58b). Onycholysis alone, withoutDimples, or discoloration, can be caused by trauma, infection, nail polish hardener, or phototoxic reactions to drugs such as tetracyclines (Abb. 8.67).

Onychomycosis and nail dystrophy

Onychomycosis or fungal infection of the nail plate (Abb. 8.132), is not as common in children as in adults. Hencenail dystrophyshould not automatically be treated as a fungal infection unless demonstrated by microscopic examination and/or fungal culture. Dystrophic nails can be the end result of many different types of inflammation of the nail matrix and often occur after discrete or more minor repetitive trauma or friction (Abb. 8.133) or from an underlying dermatosis such as psoriasis, atopic dermatitis, or lichen planus.

Median Nail Dystrophy and Habit-Tic Dystrophy

Mediannail dystrophy(also referred toSolenonychiaormedian canaliform nail dystrophy) and habit-tic dystrophy (also calledOnychotillomaniaorHabitus tic deformity) are rare conditions that usually affect the thumbs. Both disorders have a central channel-like depression or fissure of varying severity with fissures or lines extending from the central longitudinal lesion to the lateral nail edges (Abb. 7-56). In median nail dystrophy, the lines are typically described as feathery cracks resembling a Christmas tree, and in habit tic dystrophy they are described as being more horizontally arranged and irregularly spaced; However, the two disorders can appear identical, leading some experts to group them as one disorder. A transient defect in the matrix interfering with nail formation is believed to be the cause, causing the indentation or split to appear initially at the cuticle and propagate outward as the nail grows. Median nail dystrophy has been reported during isotretinoin administration^478.479and with habitual use of smartphones and tablets,⁴⁸⁰whereas habit tic dystrophy is often associated with continuous picking of the nail cuticle of the affected digit and has been described in association with guitar playing.⁴⁸¹The disorder can sometimes resolve spontaneously years later, especially after the causative trauma has subsided. Aside from preventing trauma, there is no effective treatment, although 4 months of tacrolimus 0.1% ointment resulted in significant improvement in a 19-year-old man with moderate nail dystrophy.⁴⁸²

Definition

nail dystrophycaused by psoriasis is the result of abnormal keratinization of the nail matrix and nail bed as a result of involvement of these structures in psoriasis.

incident

Nail involvement in patients with psoriasis is common. Reported incidences range from 10% to 50%.

Story

Nail psoriasis is usually asymptomatic. However, fingernail involvement can be a significant cosmetic problem, and toenail deformity can cause pain related to pressure from shoes.

Physical examination

differential diagnosis

The differential diagnosis of psoriasis of the nails includesOnychomycosis,Trauma,aging, andDystrophy as a result of eczema, or another inflammatory process in the area of ​​​​the nail fold. Fungal infections of the nail can be ruled out by a KOH preparation and culture. Otherwise, psoriatic nails can only be diagnosed with certainty if other typical lesions of psoriasis are found elsewhere. Although nail biting is the most characteristic finding of psoriasis, it is also occasionally associated with itAlopecia areata.

laboratory and biopsy

Nails are rarely examined by biopsy to confirm a diagnosis of psoriasis (Feige. 21.4B).

therapy

Treatment of nail psoriasis is difficult and mostly unsatisfactory. Therefore, therapy is often not recommended. Injecting steroids into the proximal nail fold is painful and the results are often disappointing. Topical preparations are ineffective.

course and complications

Psoriasis of the nail is a chronic condition and has a waxing and waning course. Arthritis of the distal interphalangeal joint is often associated with nail involvement. The nail is sometimes secondarily infected withCandida albicansorPseudomonas aeruginosa.PseudomonasThe infection is easily recognized by a green discoloration and is treated with 2% thymol in alcohol, one or two drops three times a day.

pathogenesis

Psoriasis is characterized by a marked acceleration of epidermal cell replication, leading to proliferation of keratinocytes. When this occurs in the nail bed, excess keratin becomes trapped under the nail plate and onycholysis occurs. The appearance of an "oil stain" is caused by keratin residue and inflammation in the nail bed. The nail pits result from involvement of the nail matrix, where psoriasis is thought to create small foci of defects in the nail plate. As the nail plate advances, these defective parts fall out, leaving the characteristic pits.

psoriasis

CONGENITAL ONYCHODYSPLASIA OF THE INDEX FINGER

Congenital onychodysplasia of the index fingers (COIF), also known as Iso and Kikuchi syndromes, was first described in 1969.^47,48Original cases were congenital, confined mainly to the index fingers, and characterized by anonychia, micronychia, and/or polyonychia (Abb. 29-7). They were non-familial and non-hereditary and had no underlying bone or joint abnormalities. Since then, the clinical criteria have been modified or expanded to include a number of additional observations.⁴⁹

Although the index fingers are most commonly affected, onychodystrophy has been reported in other fingers and toes.^50,51Malformations, rolled micronychia, hemionychogryphosis, onychoheterotopia, and polyonychia with syndactyly have also been detailed. Unlike nail-patella syndrome, abnormalities in the nail unit are more prominent on the radial aspects of the digits. A Y-shaped bifurcation of the terminal phalanx on lateral radiographs is common and characteristic of the disease.⁵²Familial cases are also documented.⁵³

The pathogenesis of congenital onychodysplasia is poorly understood. Abnormal vasculature, anomalies from an abnormal grip, external deformation from pressure on the skull, exposure to teratogens, and genetic influences have been implicated by a number of authors.⁵⁴It is quite possible that the clinical findings can be explained by one of these theories if the initiating event occurs at some point during the embryological development of the nail unit.

Osteo-Onychodysplasia

Osteo-Onychodysplasia(Nail-Patella Syndrome,Fong Syndrome) is a rare autosomal dominant disease with multiple skeletal abnormalities. The most prominent feature is posterior iliac horns, a pathognomonic finding present in most cases (Abb. 47-14A). The knees are dysplastic with absent or hypoplastic kneecaps (Abb. 47-14B), hypoplastic lateral femoral condyles and the associated valgus alignment (genu valgum). The elbows are also dysplastic, with a hypoplastic capitellum and associated radial head dislocation. The fifth metacarpals may be short. Clinical features include dysplastic fingernails, particularly of the thumb and index finger, clinodactyly, and renal disease.

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