Light therapy (phototherapy) - use with the medical purpose artificially obtained infrared, visible and ultraviolet radiation. When phototherapy is used and the natural radiation of the Sun (see Heliotherapy). The action of light energy on the human organism is determined by the intensity (the lamp power and distance to the irradiated surface), duration of exposure and depth of penetration of electromagnetic waves. The penetration depth of the light energy is different: in most areas of the red and infrared and at least ultraviolet rays.
After contact with skin light rays cause redness - erythema. Under the effect of the infrared rays erythema appears during or after a few minutes after exposure (thermal erythema). Under the action of ultraviolet rays erythema appears after a certain (2-8 hours.) latent (latent) period (PV erythema). The degree of response of the skin depends on the dose and the sensitivity of the skin to ultraviolet rays. Last varies in different parts of the body (regional photosensitivity) and descends from the skin of the chest, abdomen, back to the skin of hands and yogi. Repeated exposure lower sensitivity, so in autumn it is lower than in spring.
Reactivity of skin can be changed in certain pathological conditions: enhanced if the individual forms of eczema, some neuro-vascular lesions, increased function of the thyroid gland, while receiving some drugs (sulfonamides), weakened by chronic infectious diseases, accompanied by General exhaustion, in serious cases, modified with the defeat of the various divisions of the nervous system. After 3-4 days on the site of exposure appears pigmentation (tan), which is possible and without education erythema, due to the long-wave ultraviolet irradiation, especially solar, or artificial. The intensity of pigmentation depends on the course of the pathological process.
The mechanism of action of ultraviolet radiation - see Ultraviolet radiation. The action of visible and especially infrared radiation (see) is accompanied by the expansion of blood and lymphatic vessels, increasing blood and lymph circulation, increases metabolism and tissue temperature.
With the purpose of preventive and curative effects on the body use artificial light sources that depending on how radiation is divided into caloric and y. The calorific (heat) sources the number and composition of the emitted energy depend on the degree of heating of a radiating body. These include incandescent lamps, emitting infrared and visible rays (see Solux lamp, Minin's lamp).
The luminescent light sources glow due to electrical, chemical phenomena. To this source category are mercury-quartz lamps, bactericidal and erythema uviol (see ultraviolet Irradiators).
The readings. Visible and infrared rays is used as an analgesic and resolving tool, mainly in subacute and chronic inflammatory processes, nerve and muscle pain, as well as to enhance the metabolic processes in the body. Ultraviolet rays are used when the total exposures in the case of ultraviolet failure, to strengthen the body, increase resistance to various infections (see Votarii); in erythermal doses - as an analgesic and anti-inflammatory agent for the treatment of some forms of arthritis, diseases of the peripheral nervous system (neuritis, neuralgia, radiculitis), muscle (myositis), respiratory (bronchitis, pleurisy) systems, skin and gynecological diseases. Ultraviolet irradiation of various intensity and localization applied with metabolic disorders, tuberculosis joints, bones, lymph glands, peritonitis tubercular etiology, fibrous form of tuberculosis. Desensitizing the action of ultraviolet radiation used in the treatment of arthritis allergic origin, bronchial asthma (in the interictal period), in susceptibility to colds, bronchitis, laryngitis and other Local and General light baths (see) is prescribed for the treatment of polyneuritis, myositis, myalgias of different origin, radiculitis.
The purpose of disinfection of air, short-wave ultraviolet radiation is used in children's and medical institutions, operating, dressing.
Contraindications. The use of light, in particular the ultraviolet rays is contraindicated in active form of pulmonary tuberculosis, malignant neoplasms, heart, kidney failure, hypertension of II - III degree, sharp depletion, increased function of the thyroid gland, as well as with high sensitivity (sensitization) to light.
Light therapy in Pediatrics. Anatomical and physiological characteristics of an organism of the child cause increased sensitivity to light therapy.
The greatest caution require UV exposure; until their use is necessary to determine biodata (see). Pronounced "threshold" erythema in children of early age often appears on irradiation for 15 sec. General ultraviolet irradiation appoint premature children gradually increasing doses of 1/2 to 2 biodoses while heating lamp Solux or infrared. General ultraviolet irradiation appoint and rickets, for the prevention of respiratory catarrh, as well as in the interictal period rheumatism to raise protective forces of an organism. Local ultraviolet irradiation prescribed for chronic tonsillitis (radiation of the tonsils). In the General ultraviolet irradiations in prophylactic doses there has been improvement in appetite, sleep, indices of physical development.
Contraindications to the use of ultraviolet irradiation are the same as for adults, and, in addition, increased excitability of the Central nervous system.