Phototherapy is a medical treatment that uses specific wavelengths of light to address various health conditions. This non-invasive approach involves exposing the skin to controlled light sources. It is a well-established therapy, particularly in dermatology, neonatal care, and mental health, used to manage and treat diseases without surgical intervention.
The Basics of Phototherapy
Phototherapy uses specific light wavelengths to influence biological processes at a cellular level, triggering biochemical reactions. Ultraviolet (UV) light, especially within the UVB and UVA spectrums, is often employed.
UVB light mainly affects the outer layers of the skin, influencing cell turnover and suppressing DNA synthesis. UVA light penetrates deeper, reaching the mid and deep dermal components, including blood vessels, and can alter the function of skin cells and immune responses. Therapeutic effects include reducing inflammation, suppressing overactive immune responses by affecting T-lymphocytes and Langerhans cells, or stimulating cellular repair processes.
Conditions Treated with Light
Phototherapy is an effective treatment for a range of medical conditions, especially those affecting the skin. For psoriasis, a condition characterized by rapid skin cell overgrowth, UV light helps slow excessive cell production and reduce inflammation. Eczema (atopic dermatitis), an inflammatory skin condition, also responds to light therapy by modulating the immune response.
Vitiligo, a disorder causing patches of skin to lose pigment, can be treated with phototherapy to stimulate pigment-producing cells. Beyond skin conditions, phototherapy is used for neonatal jaundice, a common condition in newborns where high levels of bilirubin can be harmful. Blue-green light, typically in the 460-490 nm range, converts bilirubin into water-soluble forms for easier excretion, preventing potential brain damage.
Methods of Light Therapy Delivery
Phototherapy can be administered using various light sources and delivery methods tailored to the specific condition and affected body area. Broadband UVB and narrowband UVB are common types of UV light used, with narrowband UVB offering a more targeted approach. UVA light, sometimes combined with a photosensitizing medication called psoralen (PUVA therapy), penetrates deeper into the skin.
Delivery methods include full-body light boxes and localized units for hands and feet. Targeted lasers can deliver concentrated UV light to smaller, specific lesions. For infants with jaundice, light blankets or overhead lamps with blue-green light-emitting diodes (LEDs) are used, ensuring maximum skin exposure while providing eye protection.
What to Know Before Undergoing Phototherapy
Before starting phototherapy, individuals should be aware of potential side effects, including skin redness, dryness, or itching. These reactions often fade within 24 hours. A sunburn-like reaction with blistering may occur.
Eye protection is recommended during treatment sessions to prevent eye damage, such as cataracts, especially with PUVA therapy. Consistent sessions are necessary for therapeutic effects, and it may take multiple sessions to see improvement. Individuals with a history of skin cancer, lupus, sun allergies, liver disease, or those who are pregnant or nursing, should discuss potential contraindications or increased risks with their healthcare provider.