Onychogryphosis is a type of onychodystrophy characterized by deformation of the nail plate in the form of a griffin’s claw. Clinically, onychogrifosis is divided into two stages. The early one manifests itself in thickening of the nail, changing its transparency, staining in dirty yellow tones, curvature of the nail plate, often with ingrowth into the skin. The late one is accompanied by twisting of the tissues of the horny plates, the appearance of striation, pain when walking. Pathology is diagnosed clinically with blood sampling for RW and sugar, dermatoscopy is used, scraping is taken from the nail to exclude mycosis, if necessary, specialized consultations are conducted. The treatment consists in removing the nail plate.
General information
Onychogryphosis is a rare dystrophic lesion of the nail plate, mainly localized on the legs, associated with changes in the periarticular tissues, hypertrophy of the horny plates, their densification, twisting of the horny layers and curvature in the form of the claw of a mythical bird (griffin). In modern dermatological practice, the term “onychogrifosis” was introduced by the German physician and physiologist R. Virchow. As a rule, onychogrifosis is a disease of elderly and senile patients, in very rare cases it can occur even in children. Often onychogryphosis is diagnosed in athletes. A common concomitant pathology is flat feet. The pathological process has no gender and seasonal component, is non-endemic. The urgency of the problem is associated with the possible mycotic or syphilitic etiology of onychogryphosis, pain that occurs when walking, and a decrease in the quality of life of patients.
Causes
The exact cause of the disease has not been established. It is believed that onychogryphosis occurs under the influence of exogenous and endogenous triggers. The first include injuries, frostbite, tight shoes, local disruption of blood supply to the periarticular tissues, careless treatment of nail plates, anhidrosis, local skin infections. The second group includes immune disorders, skin sensitization, metabolic changes in the dermis, age-related endocrine disruptions, physiological tissue aging, chronic dermatoses, varicose veins, keratoses. Similar nail changes can also be observed with syphilis. Rare cases of congenital onychogryphosis are described, the cause of which is unidentified gene mutations. The pathogenesis of the disease has not been fully studied. The only well-established fact in the development of onychogryphosis is a violation of the nutrition of the nail plate.
If onychogryphosis is based on trauma, wearing tight shoes, frostbite, there is the formation of a sub-elbow hematoma, which mechanically squeezes the periarticular tissues, disrupting their nutrition and causing changes in the matrix of the nail. Horn cells thicken due to intracellular retention of exudate, disproportionate metabolic disorders occur in them. At the same time, damaged keratinocytes begin to secrete pro-inflammatory cytokines that initiate inflammation in the dermis. T-lymphocytes produce interleukins that enhance exudative and proliferative processes in the periarticular tissues and in the nail matrix. Swollen, changed their composition, the horny cells of the epidermis begin to divide intensively.
One layer of horn cells overtakes another, keratinocytes are layered on top of each other, changing the canvas of the nail plate, its shape and color. The resulting hyperkeratosis disrupts the connection of the nail with the nail bed. A hypertrophied nail is formed. Something similar, with the exception of the formation of a sub-elbow hematoma, occurs if the cause of onychogryphosis becomes an infection or hypohidrosis. Chronic inflammation provokes infiltration of the nail bed, stimulates the processes of keratinization in the matrix and along the entire length of the horny plate with the formation of a hyperkeratotic nail.
If onychogrifosis is provoked by endogenous triggers, then the changes in the horny plates are based on immune disorders against the background of age-related changes in the physiological properties of the skin and its appendages. The matrix of the nail becomes thinner with age, the amount of water and lipids decreases in it. In the epidermis and dermis, a part of the blood vessels is neglected. All this leads to a violation of the nutrition of the appendages of the skin, trophic disorders, changes in the chemical composition of the nail.
Against this background, any effect on the skin triggers inflammation in the dermis, enhances the process of proliferation of keratinocytes in combination with the abnormal growth of horn cells that form the nail plate. There is subcutaneous hyperkeratosis, the nail thickens, changes color, deforms, partially loses contact with the nail bed, eventually acquiring the shape of a claw. Onychogrifosis is aggravated by vascular insufficiency, which develops in many patients over 60 years of age, drug sensitization and diabetes mellitus (increased fragility of blood vessels).
Classification and symptoms
In practical dermatology, it is customary to distinguish between congenital and acquired onychogryphosis. This is important for the appointment of adequate therapy, which depends on the cause of the pathological process. Clinically, there are two stages of the development of onychogryphosis. At an early stage of the disease, there is pain in the soft tissues near and under the nail plate. Such sensations cause discomfort to patients when walking, since the pathological process is localized most often on the big toes. The pain increases with the slightest pressure on the nail plate. Over time, the nail begins to thicken, an unnatural horny growth arises, towering above the level of the nail bed. If the thickness of the nail exceeds 1 mm, it is already possible to talk about the beginning of onychogryphosis. The nail darkens, becomes dense, is difficult to process, the edges of the nail plate can grow into the skin.
In the second stage of onychogryphosis, deep transverse and longitudinal stripes appear on the hypertrophied nail plate. The color of the nail changes to dirty yellow with a black-gray tint. The horny layers begin to twist, while becoming so hard that wearing even comfortable shoes causes severe pain. It is not possible to process the nail without preliminary softening, it goes beyond the tip of the finger and begins to bend inward, taking the shape of a bird’s beak. Sometimes the direction of nail growth becomes helical or spiral, it twists. Its length reaches 4-6 cm, the surface acquires a brown hue, bumps and roughness appear on it. The shape resembles an animal’s horn. Patients cannot put on shoes without assistance, they move with difficulty. Such onychogryphosis occurs in senile and elderly patients.
Diagnosis and treatment
Onychogryphosis is diagnosed by a dermatologist or podologist. The diagnosis is not difficult due to the typical clinic and anamnesis. If necessary, specialized consultations are prescribed (endocrinologist, vascular surgeon, immunologist-allergist). Acquired onychogrifosis requires blood sampling for RW and determination of blood sugar levels (with late syphilis and diabetes mellitus, a similar deformation of the nail plate occurs). The exclusion of mycotic infection is mandatory. To do this, dermatoscopy is performed, a Wood lamp is used, a scraping from the affected nail is microscopized, or the pathological material is seeded on nutrient media.
If a secondary infection joins the manifestations of onychogryphosis, the causative agent of pyoderma is necessarily established by seeding the separated pustules with the determination of sensitivity to antibiotics. Pathology therapy can be effective only if the exact cause of onychogryphosis is clarified. The earlier the patient goes to a specialist, the better the result. The meaning of therapy is to reduce the thickness of the nail plate, return the nail to its normal shape. To do this, it is necessary to partially or completely remove the nail plate. The method of removal is chosen by the podologist. In the conservative version, first soften the nail with a special paste, applying it to the affected plate for 30-40 minutes. After that, the paste is washed off with warm water, and the softened part of the nail is removed by mechanical scraping.
The course consists of at least 3-5 procedures. At the same time, vitamins are prescribed inside, regenerating ointments based on retinol and gelatin are used externally. An alternative is keratolytic patches. In severe cases, the nail is removed completely (surgically or with a laser). The base of the nail is preserved on the hands for aesthetic purposes. Vitamins, minerals, retinol and tocopherol preparations are used inside. The course of treatment is up to 4-6 months. Prevention of onychogryphosis consists in avoiding injuries, wearing comfortable shoes, correcting concomitant diseases, proper treatment of nail plates, protecting hands from household chemicals. The prognosis is doubtful, a complete cure is often impossible.