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the therapeutic use of sunlight or optical radiation, including infrared, visible, and ultraviolet radiation; a branch of physical therapy. Luminous energy’s effect on man is determined by its intensity (strength of the source and distance to the irradiated surface), by the duration of irradiation, and by the penetration depth of electromagnetic waves. The penetration depth, which depends on the light-wave length, is greatest with infrared and visible rays and least with ultraviolet rays. Erythema, that is, redness of the skin, may appear a few minutes after irradiation, for example, by infrared rays, or two to eight hours after exposure to ultraviolet rays. The intensity of the skin reaction varies with such factors as age, the time of year and the sensitivity of the skin in different parts of the body to different kinds of rays. It can change with some pathological conditions and after the ingestion of certain medicinal substances. The irradiated area acquires a tan in three to four days.

Thermal and luminescent artificial light sources are used in phototherapy. Thermal sources include incandescent lamps that emit infrared and visible rays, general and local light baths, Minin lights, and infrared rays. The quantity and composition of the energy released by these sources depend on the temperature of the radiating body. Luminescent sources, in which radiation is achieved by electrical, chemical, and other processes, include mercury-vapor lamps, luminescent erythematous lamps, and arc bactericidal lamps.

Ultraviolet irradiation, both local and general, is used to compensate for an ultraviolet-radiation insufficiency and to increase resistance to various infections, for example, influenza. It is used as an analgesic and antiphlogistic in treating diseases of the joints, the peripheral nervous system (neuritis, neuralgia, radiculitis), the muscular system (myositis), and the respiratory system (bronchitis, pleurisy), as well as in treating skin diseases, gynecologic and metabolic disorders, and some forms of tuberculosis. Ultraviolet irradiation is used in pediatrics in preventing rickets and acute respiratory diseases, in increasing the body’s defensive mechanisms against rheumatic fever between attacks, and, together with antirheumatics, in treating rheumatic fever during its acute phase. Thermal procedures and visible and infrared rays are used as analgesics and resorption agents primarily in treating subacute and chronic inflammatory diseases, neuralgia, and muscular pains.

Phototherapy is contraindicated in treating the active form of tuberculosis, neoplasms, pronounced heart failure, the second and third stages of hypertension, acute exhaustion, increased thyroid function, renal disease and insufficiency, and photopathy (a diseased condition caused by light).


References in periodicals archive ?
The global phototherapy equipment market size is expected to reach at USD 845.7 million by 2026 registering a CAGR of 6.3%.
To study the electrolyte changes in neonates receiving phototherapy for neonatal jaundice at Sardar Vallabhbhai Patel Postgraduate Institute of Pediatric (SVP PG IP), SCB Medical College and Hospital, Cuttack, Odisha.
Dr Radomska said: "Home phototherapy treatment is not routine in the UK, but it could benefit more babies across the country if other hospitals considered treating them in this way, with the right training and safety measures in place for parents.
In one study, patients who received narrow-band UVB had an increase in vitamin D levels that could contribute to photo-induced melanogenesis, and an open-label study indicated that patients who took vitamin D daily (without phototherapy) for 6 months had an increase of repigmentation over time.
Term and late-preterm babies, who received phototherapy due to hyperbilirubinemia in the Neonatal Intensive Care Unit of Marmara University Medical Faculty between January 2015 and December 2015, were enrolled in this prospective study.
BiliChek measurement was done while all phototherapy lights were turned off.
Beale believes that innovation in this traditional phototherapy lies in the clinical application and the technical delivery of the light, as he explained: 'Typically, a low intensity of light over a large area is required, with high efficiency to reduce thermal load,' he said.
Table 1 SCORAD score group A (betamethasone valerate 0.1%) and group B (NB-UVB phototherapy).
Phototherapy is known to be an effective treatment for psoriasis, mycosis fungoides, and vitiligo.
The Clarify System is the first and only phototherapy system that uses an app on the patient's smartphone (iOS or Android) to manage the dose, frequency, and duration of UVB light therapy, helping to ensure that patients are adherent to the prescribed treatment.
Hyperbilirubinemia is common during the neonatal period and sometime requires treatment with either phototherapy or exchange transfusion.