Palmoplantar keratodermas is a set of skin diseases with a predominant violation of the keratinization process in the epidermis. Clinically, the disease is manifested by focal or diffuse keratoelastoidosis of skin areas, most often on the palms and soles, in the absence of sebaceous glands. The primary element is a polygonal papule that practically does not rise above the level of healthy skin, up to 3 mm in diameter, yellowish-pink in color, rough when stroking the skin. The features of the course of dermatosis depend on its variety. Diagnosis is carried out using diascopy and histology. Treatment is long-term, complex, aimed at correcting the process of keratinization.
Palmoplantar keratodermas is a heterogeneous group of rare chronic skin dermatoses resulting from impaired differentiation of epidermal cells. There are no data on the frequency of occurrence, prevalence, gender coloration, endemicity, age segment, seasonality of pathology. There are acquired and hereditary types of palmoplantar keratodermas, and an accurate diagnosis of the type of ailment in this case is of fundamental importance for the adequate treatment of patients.
The founders of natural-scientific approaches in the study of skin diseases are rightfully considered three of the most famous representatives of the dermatological school: Joseph Jacob Film, who based the classification of skin diseases on the principle of their morphology; Ferdinand von Gebr, classifying diseases on a pathoanatomic basis; Jean Darrier, who proposed to take into account the relationship between the cause of the disease and the mechanism of its development. It is the principle of diagnosis according to J. Daria that formed the basis for the classification of sporadic (acquired) palmoplantar keratodermas. Genetically determined palmoplantar keratodermas is the prerogative of medical genetics. However, today there are no generally accepted criteria for the diagnosis of hereditary dermatoses.
The causes of palmoplantar keratodermas are individual for each variety, have not been fully studied to date. As for genodermatoses, these are diseases with an autosomal dominant and autosomal recessive type of inheritance, which are caused by mutations in the genes responsible for the processes of keratinization. Sporadic forms of palmoplantar keratodermas occur against the background of impaired synthesis of vitamin A, dysfunction of the endocrine glands, infections, tumors.
The essence of pathology lies in the failure of a well-established process of the death of epidermal cells. From the point of view of evolution, keratinization is the protection of the body from external negative influences. For example, oxygen or the sun come into contact with already dead cells of the epidermis, which the skin loses every second, leaving the internal balance of the body intact. The birth of protective cells occurs in the basement membrane, then part of them, losing the nucleus and other components, ages, rises to the surface of the skin, filling up with keratin along the way, tightly binding together and simultaneously losing the remaining moisture. In the uppermost layer of the epidermis, they look like a dense monolith, easily disappearing from the skin at the slightest touch or movement.
In the pathological process, for reasons that are unclear to the end, this sequence is disrupted: the cells of the epidermis begin to multiply at double speed, do not have time to go through the entire life cycle to the end, form dense cellular keratin plates that are tightly soldered together and remain on the surface of the skin, causing inflammation phenomena.
There is no generally accepted classification of keratoderma in dermatology. Based on the clinical manifestations of the disease and taking into account the cause of its occurrence, all palmoplantar keratodermas can be divided into diffuse and local. Diffuse palmoplantar keratodermas is characterized by a continuous lesion of the skin of the palms, local form – hyperkeratosis of individual areas of the skin. In each of these groups, the most common varieties of palmoplantar keratodermas can be distinguished.
Genetically determined diffuse palmoplantar keratodermas, which are based on a gene mutation of keratinization, include:
- Palmoplantar keratodermas of the Unna—Toast (keratoma congenital palmar-plantar), is inherited autosomally dominant, clinically manifested in newborns by slight peeling, hyperhidrosis.
- Meleda palmoplantar keratodermas (hereditary transgradient keratosis) is inherited by an autosomal recessive type, a distinctive feature is the spread of the pathological process to the back of the hands and feet, incest plays a role in the development of the disease. Clinically manifested by flaky erythema, combined with atopy, pyoderma.
- Papillon—Lefebvre palmoplantar keratodermas is inherited autosomal recessive, occurs against the background of thyroid and pancreatic dysfunction. Clinically manifested by palmar-plantar hyperkeratosis with slight peeling, the process tends to spread, accompanied by dystrophy of nails and teeth.
- Von Winkel’s mutating palmoplantar keratodermas is inherited autosomally dominant, clinically characterized by thick horny layers in the palms and soles, accompanied by hyperhidrosis, deep striation of the skin with possible amputation of the phalanges. The process tends to spread, nails and hair are affected (baldness).
- Palmoplantar keratodermas follicular spiny is a hereditary dermatosis affecting the skin of the face, eyelashes, and scalp. Clinically manifested by small corneal plugs, baldness. Mucous membranes are not involved in the process.
- Erythroceratodermia variable figured is a rare type of hereditary dermatosis, inherited autosomally dominant. Clinically manifested by a rash of reddish-yellowish foci of geographical configuration, consisting of papules that tend to peripheral growth. Foci ulcerate, itch, combs join, secondary infection.
Diffuse sporadic palmoplantar keratodermas acquired in the course of vital activity may include:
- Idiopathic palmoplantar keratodermas is a dermatosis that occurs during puberty, clinically manifested by islets of calcaneal hyperkeratosis, lesions of the skin of the palms and soles.
- Palmar-plantar infectious palmoplantar keratodermas occurs after severe infections, is characterized by excessive thickening of the skin of the palms and soles in the form of erythematous foci with clear boundaries, disappears spontaneously.
- Radiation palmoplantar keratodermas is a disease of radiologists and X–ray technicians with hyperkeratosis of certain areas of the skin of the palms and soles.
- Senile palmoplantar keratodermas occurs in the elderly, localized in the face, forearms, palms, soles in the form of separate dense, dry, warty plates soldered to the underlying tissues. When you try to remove them, they bleed. These are the harbingers of skin dystrophy, its possible malignancy.
The group of local keratodermies also includes genodermatoses and acquired keratodermies. Genodermatoses are located exclusively on the palms and soles, without a tendency to spread; they can be represented by the following varieties:
- Keratoderma spotted disseminated Buschke—Fischer—Brauer is inherited autosomally dominant, clinically characterized by pinpoint corneal papules transforming into crater-shaped corneal plugs, localized mainly on the flexor surfaces of the fingers and feet.
- Werner’s disease is a hereditary palmoplantar keratodermas characterized by nail damage.
- Touraine polyceratoderma is a hereditary dermatosis from the group of ectodermal dysplasia localized on the palms and soles.
Acquired local palmoplantar keratodermas are characterized by limited papular rashes of the skin. These include:
- Tar palmoplantar keratodermas is an occupational disease (patients deal with crude coal tar). It manifests itself in the form of warty formations around the hair follicles on the back of the hands, genitals, forearms. It can transform into skin cancer.
- Crocker—Adamson’s spiny lichen is a rare dermatosis characterized by corneal plugs with fragments of hair in the center, localized on the neck and extremities, tends to self-resolve.
- Palmoplantar keratodermas follicular contagious Morrow—Brook is a peeling papular dermatosis that occurs on the forehead, nape, trunk, in the folds of the skin, spontaneously resolves.
Clinical manifestations of palmoplantar keratodermas correspond to the type of pathology. However, the common features of all palmoplantar keratodermas are hyperkeratosis and peeling. In most cases, the disease is diagnosed in childhood, there is no clear age limit. The primary element is erythema, against which urticary elements appear, covered with horny scales. The sizes of the primary elements vary, the color differs in a variety of shades: from pink to yellow. The elements of the rash merge with each other: some diffusely, forming a continuous hyperkeratotic surface, others – into small, local foci of hyperkeratosis. The process is localized most often on the palms and soles, but may have a different localization.
The resolution of the process is possible in a “dry” and “wet” way. Completely dehydrated cells have an inelastic surface, on which cracks and hemorrhagic crusts often occur. Cells with moisture residues form erosion, wetness. Secondary infection is layered. The pathological process resolves spontaneously over time or acquires a chronic, recurrent course.
Diagnosis and treatment
There is no specific diagnosis. When diagnosing palmoplantar keratodermas, it is important to distinguish the etiology of the disease. Genodermatoses require the advice of a geneticist. With acquired palmoplantar keratodermas, anamnesis, clinic, triggers are taken into account, less often – the results of histological examination. In difficult cases, a dermatooncologist examination is necessary (the possibility of malignancy of the process). Differentiate palmoplantar keratodermas with other forms of keratosis, psoriasis, Deverji’s disease, dyshydrotic eczema.
There is no radical therapy for genodermatoses. With the dominant type of inheritance, RNA interferences blocking defective alleles are available. Sporadic forms are treated comprehensively, according to individual schemes. The purpose of therapy is to eliminate the cause (infections, toxins, metabolic disorders, exacerbation of endocrine diseases), correct the intensity of keratin formation, increase the patient’s immunity, improve well–being. The basis of therapy consists of retinoids, vitamin therapy (vitamin D, C, PP), angioprotectors, immunocorrectors. When a secondary infection is attached, antibiotics are prescribed. Locally, dermatologists use keratolytics, urea-based ointments that improve skin hydration, regular bran baths, mechanical keratolysis. The patient should be under constant supervision of doctors in order not to miss the possible malignancy of keratoderma.