As the name suggests, this treatment uses natural or artificial light. The simplest and easiest form of phototherapy involves exposing your skin to controlled amounts of natural sunlight. Other forms of light therapy include the use of artificial ultraviolet A (UVA) or ultraviolet B (UVB) lights either alone or in combination with medications.

The use of light of optimum wavelength is fundamental to the effectiveness of phototherapy. The source of blue light should have a peak output at about 450 nanometers and a wavelength range not wider than 400 to 520 nanometers.

The narrowband UVB phototherapy is a useful and well-tolerated treatment for children with severe or intractable inflammatory skin disease.

Indications for phototherapy:

Neonatal jaundice: Jaundice or hyperbilirubinemia occurs when bilirubin, a yellow pigment created as a byproduct of the normal breakdown of red blood cells, cannot yet be processed by a newborn's liver and builds up in the blood, turning the skin, whites of the eyes and mucous membranes yellow. During phototherapy, the treatment of choice for jaundice, babies are placed under blue lights (bili lights) that convert the bilirubin into compounds that can be eliminated from the body.

• Psoriasis.
• pityriasis lichenoids
• Atopic dermatitis.
• Seasonal affective disorder.
• Melanocytic nevus.
• Vitiligo.
• Mycosis Fungoides.

Aggressive phototherapy reduces the odds that tiny premature infants will develop neurodevelopmental impairment such as cerebral palsy, blindness, deafness or physical or mental challenges.

Other Dermatoses like seborrhoeic dermatitis, pityriasis lichenoides, nodular prurigo, lichen planus, chronic graft-versus-host disease, scleroderma, necrobiosis lipoidica, chronic urticaria and urticaria pigmentosa.

The combination of laser therapy and phototherapy are used are used in treatment of certain oncological diseases in children. This method has a significant anti-inflammatory and anesthetic effect as well as powerful regenerative influence on tissues. Its application decreases considerably the duration of treatment of complications when treating children's malignant tumors and enables to keep to scheduled terms of complex treatment.

Long-term light therapy has many harmful effects:

• Premature skin aging
• Increased risk of skin cancer.
• It also causes skin moles.
• It can cause bronze baby syndrome:
• Apoptosis of human dermal endothelial cells.
• Suicidal tendencies as a complication of the light therapy for seasonal affective disor