Pachyonychia is a dermatological condition of various origins, which manifests itself by changing the structure, thickness and shape of nails, which in some cases leads to their loss. The symptom of this condition is a thickening, sometimes very significant, of the nail plate with deformation and discoloration – such disorders, depending on their causes, can capture one nail or several (up to all). Diagnosis is made on the basis of the results of an examination by a specialist, a variety of clinical studies can be used to determine the etiology of the disease. The treatment depends on the causes of nail changes. For some forms of etiotropic therapy does not exist.
Pachyonychia is one of the forms of onychodystrophy, which is characterized by thickening of the nail plate, changing the shape and sometimes the color of the nails, in severe cases can lead to their loss. This condition can be both acquired and congenital, including those caused by certain genetic diseases. Back in the early 20th century, German dermatologists Yadasson and Levandovsky discovered hereditary pathology, one of the main manifestations of which was thickening of the nail plates. Pachyonychia is considered a fairly common condition in dermatology. Often accompanies some skin (psoriasis, eczema and others) and metabolic diseases. In some cases, it may occur as a component of age-related changes in the elderly. The age of development of pachyonychia, the prevalence of the lesion and other features of the clinical course of this condition vary quite a lot depending on the causes of the disease, so some experts consider pachyonychia as a symptom of certain disorders, and not as an independent dermatological pathology.
The main cause of the development of pachyonychia is a violation of nutrition or formation of the nail plate, which is externally manifested by its thickening, deformation, hyperkeratosis of the skin under the nail and other symptoms. In the case of acquired forms of this condition, the cause of the development of changes may be infection of the nail with a fungus, chemical exposure and chronic inflammation of the nail roller – it is in it that new tissues of the nail plate are formed. Etiological factors of acquired forms of pachyonychia are also psoriasis, eczema, lichen planus and other conditions in cases where they affect the nail roller and the bed. In elderly people, thickening of the nails occurs due to impaired microcirculation and lymph outflow, which also leads to the incorrect formation of new tissues of the nail plate. At a young age, diabetes mellitus, other metabolic or endocrine diseases may act as a cause of deterioration of microcirculation leading to acquired pachyonychia.
A special case is the so-called congenital pachyonychia, also known as Jadasson-Lewandowski disease. This is a genetically heterogeneous condition that has various mechanisms of inheritance and pathogenesis, characterized by numerous disorders of the process of keratinization of the skin and their appendages. One of the leading symptoms of this pathology is pachyonychia, the cause of which is defects in the molecules of certain types of collagen, impaired absorption of certain vitamins and the action of other factors, depending on the type of genetic defect. Often, such a genetic disease eventually leads to the loss of nails.
The main manifestation of pachyonychia is thickening of the nail plate on one, several or all nails (depending on the etiology of this condition), hyperkeratosis of the skin of the nail bed and, as a rule, deformation and discoloration of the nail. With psoriasis, eczema and lichen planus, nail lesions are accompanied by symptoms of the underlying disease: various skin rashes, peeling, papular and vesicular formations, the appearance of plaques. In this case, the pathological process usually captures the area of the nail roller, causing chronic paronychia, which subsequently provokes the development of pachyonychia. Thickening of the nail occurs on the fingers or toes affected by the underlying disease, pachyonychia is not detected in healthy areas.
In some cases, pachyonychia is provoked by prolonged exposure to nails of various chemical compounds, for example, alkalis. They lead to loosening of the structure of the nail plate, resulting in its thickening. Aggressive compounds can act on the periarticular roller, causing its inflammation, which ultimately also provokes a violation of nail growth. At the same time, pachyonychia can act as an occupational disease and affect several or all of the nails on the hands. A disease of this type on the toes is extremely rare. Pachyonychia of elderly people develops very slowly over many years, accompanied by yellowing of the nail and loss of its transparency. There are indications that smoking and other bad habits can accelerate the development of such a disorder. Similar manifestations are characterized by pachyonychia caused by diabetes mellitus or microcirculatory disorders.
The most striking symptoms are found in congenital forms of pachyonychia or Jadasson-Lewandowski disease. Since this is a genetically heterogeneous condition, several clinical forms of the disease are distinguished. The true Jadasson-Lewandowski syndrome is characterized by pronounced pachyonychia on the fingers and toes, soreness in the foot area, hyperkeratosis on the palms and soles. Some types of pathology are also manifested by corneal ulceration and cataracts. Another form of congenital pachyonychia (Jackson-Lawler type) often leads to early, sometimes even intrauterine development of teeth, mental retardation and focal alopecia. Thickening of nails in all forms of the disease occurs in early childhood and is very difficult, the thickness of the nail plate reaches a centimeter or more. Severe deformation over time leads to the loss of nail plates, both on the upper and lower extremities.
It is not difficult for a dermatologist to determine the presence of pachyonychia, when examined, a significant thickening of one or more nails, deformation of the plate, a change in the structure and color of this skin derivative is immediately revealed. For successful treatment, it is necessary to find out the cause of the pathology, for which a complete dermatological examination of the patient is performed, questioning and studying the anamnesis (including hereditary to exclude hereditary forms of the disease). Sometimes they resort to methods of genetic diagnosis. Such a wide range of different diagnostic techniques is due to the significant polyetiology of pachyonychia.
During a dermatological examination, signs of other diseases can be determined: chronic or candidamycotic paronychia, eczema, psoriasis, lichen planus, etc. If they affect the skin on the distal phalanges of the fingers, it almost always leads to paronychia sooner or later. In some cases, there may be nail changes without signs of other dermatological diseases – this mainly happens with diabetes mellitus, microcirculatory disorders and age-related pachyonychia. There may also be signs of measurement or endocrine disorders: obesity, striae on the surface of the abdomen, neck and thighs, atypical location of fat deposits.
If pachyonychia is congenital, other manifestations of this genetic disease are determined when examining the patient. Hyperkeratosis of the sole with the development of soreness is most often observed, signs of hyperhidrosis can be detected on the palms. With more severe forms of congenital pachyonychia, patients may have lesions of other organs and systems: mental retardation, violation of the formation of teeth, visual impairment. Pachyonychia of genetic etiology is detected already in early childhood, over time it actively progresses, the thickness of the nails on the hands and feet increases, there is a deformation of the nail plates and their further loss. Methods of genetic determination of the disease are used to confirm the diagnosis.
The elimination of pachyonychia largely depends on the therapy of the condition that caused its development. It is necessary to fully treat paronychia, excluding contact with aggressive substances. According to the indications, generally accepted methods of therapy for psoriasis, eczema, lichen and other dermatological conditions are used, one of the manifestations of which may be thickening of the nail plate. With the ineffectiveness of such therapeutic measures and with congenital pachyonychia, mechanical treatment of nails is used to correct their thickness and shape (various rasps and nail files). Corrective procedures can be facilitated by treating the nail plate with solutions of urea, salicylic or fruit acids. There are indications that the administration of retinol and tocopherol drugs can significantly slow down the development of nail deformity even with genetically determined pachyonychia.
Prognosis and prevention
The prognosis of pachyonychia regarding recovery is uncertain and is strongly dependent on the causes of this condition. With effective therapy of the underlying disease, a thickened nail may eventually be replaced by a normal nail plate. The hereditary form of pachyonychia has a more unfavorable prognosis, usually most patients lose their nails sooner or later, in addition, violations from other organs and systems are possible. Prevention of acquired pachyonychia includes timely treatment of inflammation of the nail roller and other dermatological diseases, the use of protective equipment in contact with hands or feet with chemically aggressive substances.