Pigment xeroderma( sometimes referred to as malignant lentigo, reticular progressive melanosis, pigmentary atrophoderma) is a fairly rare skin disease that is hereditary. The condition of the skin affected by xeroderma is considered precancerous.
In the overwhelming majority of cases, this disease, which is of a family nature, affects offspring born from a closely related marriage. Cases of pigmentary xeroderma are characteristic of isolates - isolated human populations formed either due to geographical location or religious beliefs.
What is pigmentary xeroderma?
As a genetically determined disease, the xeroderma is characterized by the presence of a hereditary defect, the essence of which is that in the body of the sick person either enzymes that neutralize the harmful effects of ultraviolet radiation on the skin are absent or practically do not work.
Photo pigmentary xeroderma in the child
Due to the mutation that occurred in the proteins responsible for the restoration of tissues damaged by the aggressive action of ultraviolet rays, mutated cells become more and more. Accumulating year after year, damaged cells and tissues provoke the development of skin cancer.
High sensitivity to ultraviolet radiation is one of two well-studied harmful factors contributing to the development of xeroderm .The second such factor is the same high sensitivity to ionizing radiation( radiation).
Both of the above factors lead to:
- pigmentation disorder;
- cornification of the skin;
- atrophic changes in the epidermis;
- of connective tissue dystrophy;
- cellular atypia;
- is a malignant process.
- The most common cause of the development of xeroderma is the autosomal gene , transmitted to the child from parents who are close relatives. In this case, they speak about the family nature of the disease.
- Deficiency or absence of the enzyme UV endonuclease in connective tissue cells ( fibroblasts) of a diseased person.
- In some patients, the development of xeroderma can cause to lack a RNA polymerase .The disease most often develops due to the action of ultraviolet rays with a wavelength of 270 to 320 nm.
- There is a suggestion that xeroderma may develop due to an increase in the number of porphyrins in the internal biological environment of the human body, as well as due to the ingress of photosensitizers ( photosensitizers) into it.
Clinic and symptomatology of the disease
In the clinical course of xeroderma, three stages are clearly distinguished, smoothly passing from one to the other.
- The first signs of this constantly progressing illness appear in children of two-three years of age ( cases of later manifestations are rare) after prolonged exposure to the sun. Most often this occurs in the spring or summer, during the period of the highest solar activity. Open areas of the skin are covered with a large number of peeling spots, eventually replaced by uneven hyperpigmentation( reminiscent of lentigo) and freckles. After each repeated irradiation, these manifestations intensify.
- After several years, the clinical manifestations of xeroderma are activated. This means entering the disease in the second stage. This stage is characterized by the appearance on the skin of the patient of foci of atrophy, vascular asterisks and hyperpigmented sites, which makes them quite variegated. The appearance of the skin is in many respects similar to the manifestations observed in chronic radiation dermatitis. Some parts of the skin are covered with cracks, ulcers, crusts and spots. They can appear sprouting, resembling warts. Together with the skin, cartilage and connective tissues are affected. Thinning of the cartilage of the nose and the auricles is attenuated, the natural openings of the mouth and nasal passages are deformed. As the xeroderm progresses, blepharitis develops, cases of eyelid eversion, ulceration of their mucous membranes, accompanied by loss and cessation of eyelash growth, are observed. The process is often accompanied by increased photophobia, lacrimation and opacity of the cornea.
- The last stage of xeroderma falls on adolescence and adolescence. During this period, benign and malignant neoplasms( basal cells, endothelioma, fibromas, melanomas, angiosarcomas, trichoepitheliomas, keratomas, etc.) appear on the affected tissue sites. Warty growths, very often appearing on the skin of patients, differ in their increased tendency to malignancy and metastasis in internal organs.
With Reed's syndrome, the underlying disease is associated with a slowed growth of the skeleton, a decrease in the size of the skull( microcephaly) and a significant delay in the mental and mental development of the child.
The most severe neurological form of pigmentary xeroderma is xerodermic idiocy( specialists often refer to it as De Sanctis-Kakkione syndrome ).In the clinical picture of this form of the disease, there are pronounced disorders in the work of the central nervous system, accompanied by a number of characteristic skin manifestations. With xerodermic idiocy, the presence of:
- underdevelopment of the cerebellum and pituitary gland;
- growth retardation( dwarfism);
- slowing puberty( as a rule, girls are underdeveloped ovaries, in boys - testes);
- reflex and coordination disorders;
- frequent miscarriages during the childbearing age.
- The leading diagnostic method for detecting pigment xeroderma is the examination of the skin with a special optical-mechanical device - a monochromator. The purpose of the examination is to reveal the special sensitivity of the skin to the effects of ultraviolet rays.
- To make sure the diagnosis is correct, the dermatologist directs the patient to a biopsy - a laboratory examination of the tissues that make up the cutaneous neoplasms. For laboratory analysis, select the most typical, newly formed elements, trying to make their removal as inconspicuous as possible.
When performing a puncture biopsy, use a syringe with a hollow needle. In this case, a punctate drop of fluid taken from a fresh cutaneous neoplasm undergoes a laboratory study.
- Samples of tissues taken during a biopsy are subjected to a histological examination. The ultimate goal of histology is the conclusion about the possibility and necessity of further therapy, as well as the likely outcome of the disease. In the course of a histomorphological study, the stage of the disease, the depth of tissue damage, the condition of the cells surrounding the distant tumor are revealed. At the end of the study, a histological conclusion is made, necessarily containing a microscopic description and a nosological conclusion.
- Disease diagnosed at an early stage is treated on an outpatient basis, periodically visiting a dermatologist. At this stage, the most commonly prescribed synthetic antimalarial drugs( for example, resichin, hingamin, delagil), which have the ability to reduce the sensitivity of skin to the effects of sunlight.
- For the purpose of strengthening immunity, vitamin therapy is prescribed: nicotinic acid( vitamin PP), retinol( vitamin A), vitamins of group B.
- Ointments with corticosteroids are used to treat flaky skin, to affect the warty growths - ointments with cytostatics. The active substance of these ointments acts depressingly on the processes of growth and division of all kinds of cells( including malignant ones).
- With periodic exacerbation of the disease, the patient is prescribed a course of antihistamines( suprastin, dimedrol, tavegil) and desensitizing agents( intravenous 10% calcium chloride and sodium thiosulfate).
- To prevent the aggressive influence of ultraviolet radiation in the period of the highest insolation, a number of photoprotective sprays, creams and ointments( for example, salol or quinine ointment) are prescribed.
- When the tumor process progresses, the patient falls under the supervision of an oncologist.
- Patients with De Sanctis-Kakkione syndrome are treated in specialized clinics under the supervision of a neuropathologist.
- In order to prevent rapid malignancy of the tumor process, the patient needs constant follow-up at a whole group of specialists. This group should include: an oncologist, a dermatologist, a neuropathologist and an ophthalmologist.
- Warty papillomatous neoplasms, which have an extremely high tendency to malignancy( malignancy), are subject to timely radical removal. To this end, methods of cryodestruction( freezing with liquid nitrogen), laser therapy and electrocoagulation are widely used. Laser therapy consists in the action of a directed laser beam with a certain wavelength on the problem area of the skin. Only the problem zone is affected. Healthy skin areas do not suffer at all. The procedure of electrocoagulation is reduced to cauterization of the above-mentioned sprouting electrical current. In this case, not only the removal of dangerous neoplasms takes place, but also thermal cauterization of the blood vessels feeding them, completely eliminating the possibility of bleeding.
Prognosis and prophylaxis of
In the overwhelming majority of cases of pigment xeroderma, the prognosis is unfavorable: 75% of young patients do not live to the age of fifteen, but some patients managed to survive up to fifty years of .