Light Therapy (Phototherapy)

Struggling with stubborn skin conditions like psoriasis or eczema, or perhaps the winter blues known as SAD? It's frustrating when treatments don't work. Light therapy, or phototherapy, offers a science-backed approach using specific light wavelengths. ^{[1] [2]}

What is Light Therapy (Phototherapy)?

Light therapy, also known as phototherapy, uses specific wavelengths of light, often ultraviolet (UV) or visible light like red or blue, to treat various medical and skin conditions. ^[3] It's a recognized treatment for issues like psoriasis, eczema, seasonal affective disorder (SAD), and newborn jaundice. ^[6]

Think of it as using light's energy in a controlled way to trigger beneficial biological processes. ^[5]  Let's dive into how this works and what it can do, cutting through some of the hype you might see online.

How Does Light Therapy Work?

Confused about how shining a light can actually change things in your body? You're not alone. It's not magic; it's biology!

Light therapy works by exposing the skin or eyes to specific wavelengths of light. ^[5] This light energy is absorbed by cells, triggering biological processes like slowing skin cell growth, reducing inflammation, affecting mood-regulating chemicals, or stimulating cellular energy production (ATP). ^[4]

The exact mechanism depends on the type of light and the condition being treated:

Skin Conditions (UV Light)

• Mechanism: UV light, particularly UVB, penetrates the skin and slows down the rapid growth of skin cells seen in conditions like psoriasis. It also suppresses the activity of immune cells in the skin that cause inflammation in eczema and psoriasis. UVA light penetrates deeper and is often used with a photosensitizing agent (PUVA) for more severe conditions. ^[4]
• How it Helps: Reduces scaling, redness, and itching associated with psoriasis and eczema. Can also help repigment skin in vitiligo. ^[4]

Mood & Sleep (Visible Light)

• Mechanism: Bright light, usually mimicking sunlight (without harmful UV), affects the brain's chemistry. It's thought to influence serotonin (a mood regulator) and melatonin (a sleep hormone), helping to reset the body's internal clock (circadian rhythm) . ^[5]
• How it Helps: Alleviates symptoms of Seasonal Affective Disorder (SAD) and can help with non-seasonal depression and certain sleep disorders. ^[5]

Cellular Energy & Repair (Red/NIR Light)

• Mechanism: Red and near-infrared light penetrate tissues and are absorbed by mitochondria, the "powerhouses" of cells. This stimulates increased production of ATP (cellular energy) and nitric oxide release. ^[10]
• How it Helps: Increased energy allows cells to function more efficiently, promoting tissue repair, collagen production, reducing inflammation, and improving blood flow. Used for skin rejuvenation, wound healing, and potentially pain relief. ^[6]

What Conditions Does Light Therapy Treat?

Wondering if light therapy is just for skin or if it can help with other issues? You might be surprised by the range of applications.

Light therapy is used for various conditions, including skin disorders (psoriasis, eczema, vitiligo, acne), mood disorders (SAD, non-seasonal depression), sleep disorders, newborn jaundice, and even some cancers (photodynamic therapy). ^[3]

Here's a breakdown of common uses:

Note: Evidence levels are simplified. Always consult a healthcare professional.

Is Light Therapy Safe? Are There Side Effects?

Concerned about potential risks? That's smart. While generally safe when used correctly, light therapy isn't completely risk-free. ^[6]

Potential side effects depend on the type of light therapy. UV therapies can cause redness, dryness, itching, burns (like sunburn), and long-term risks include premature skin aging and increased skin cancer risk (especially with PUVA). Bright light therapy for SAD can cause eye strain or headaches. Red/Blue LED therapy has minimal side effects, mainly temporary redness.

Let's break down the risks:

UV Phototherapy (UVB, PUVA)

• Short-Term: Redness (erythema) that usually fades in 24 hours, itching (pruritus), dry skin (xerosis), burning/blistering if dose is too high, nausea (with oral psoralen for PUVA). Folliculitis (infected hair follicles) can occur Eczema might temporarily worsen. ^[9]
• Long-Term: Premature skin aging (wrinkles, age spots) with prolonged use. Increased risk of skin cancer (basal cell, squamous cell, potentially melanoma), particularly associated with high cumulative doses of PUVA. However, most studies haven't found increased risk with NB-UVB or UVA1 alone. ^[8]
• Contraindications: History of skin cancer, certain medical conditions (like lupus), allergy to sunlight, taking photosensitizing medications, pregnancy (caution needed), liver disease (for PUVA). Eye protection is crucial.

Bright Light Therapy (SAD)

• Side Effects: Generally mild and transient. Can include eye strain, headache, nausea, agitation, or feeling "wired". Usually manageable by adjusting timing or duration.
• Precautions: Should be used cautiously in bipolar disorder as it could trigger mania. Patients with pre-existing eye conditions (glaucoma, cataracts, retinal disease) should consult an eye specialist first Devices should filter out UV light.

LED Therapy (Red, Blue, NIR)

• Side Effects: Considered very safe with minimal side effects. Temporary redness or mild irritation might occur, but usually resolves quickly Blue light  may cause hyperpigmentation in darker skin types, so caution is advised. Eye protection is often recommended, especially with masks. ^[7]

Key takeaway: Always follow device instructions and ideally, consult a healthcare professional before starting phototherapy, especially UV treatments. They can assess your suitability and recommend appropriate protocols and safety measures. ^[8]

How Do I Choose a Light Therapy Device?

Thinking about trying light therapy at home? The market is flooded with devices, making it tough to choose. Don't get dazzled by marketing hype!

Choosing the right device depends on your goal. Consider the type of light (UVB, bright white, red/NIR, blue), certifications (FDA clearance/approval, CE mark), light intensity/power density, wavelength(s), treatment area size, and ease of use.

Let's cut through the noise with practical tips:

1. Define Your Purpose

• Skin Conditions (Psoriasis, Eczema): You'll likely need a prescription UV (usually NB-UVB) device. Recent studies show home NB-UVB is as effective as office treatment. Talk to your dermatologist!
• SAD: Look for a "light box" specifically designed for SAD. It should provide 10,000 lux intensity and filter out UV light Consult your doctor first, especially if you have bipolar disorder or eye conditions.
• Acne: Blue and/or Red LED devices are common. Blue targets bacteria, red reduces inflammation.
• Anti-aging/Pain/Wound Healing: Red and/or Near-Infrared (NIR) LED devices. Wavelengths around 630-670nm (Red) and 810-850nm (NIR) are often cited for efficacy.

2. Check Key Specifications

• Wavelength(s): Crucial for effectiveness. Ensure the device emits the correct nanometers (nm) for your condition (e.g., ~311nm for NB-UVB, ~660nm & ~850nm for Red/NIR, 10,000 lux broad spectrum for SAD).
• Intensity/Power Density (Irradiance): For LED devices (Red/NIR), this is measured in mW/cm². Higher power density might mean shorter treatment times, but ensure it's safe. Look for devices providing at least 20-100 mW/cm² at a relevant distance. For SAD boxes, 10,000 lux at a specified distance (e.g., 16-24 inches) is standard.
• Certifications: Look for FDA clearance/approval (indicates safety/efficacy review for specific uses) or CE marking (Europe). Be wary of devices making medical claims without backing.
• Treatment Area & Device Type: Handheld wands for targeted spots, masks for the face, panels for larger areas, or full-body units Choose based on convenience and need.

3. Consider Quality & Usability

• Reputation & Reviews: Research the brand. Look for independent reviews, not just testimonials on the seller's site.
• Ease of Use: Will you actually use it consistently? Consider portability, treatment time, and comfort.
• Safety Features: Automatic shut-off timers, adequate UV filtering (for SAD boxes), eye protection included (especially for masks).

REDDOT Focus: As a manufacturer with 15 years in LED therapy, we supply businesses (B2B, OEM/ODM) with high-quality, certified (FDA, CE, ETL, FCC, ROHS, ISO13485) devices and components [Self-declared]. We prioritize correct wavelengths and high irradiance, offering customization for partners needing reliable phototherapy solutions.

Hitimisho

Light therapy offers diverse applications, from treating skin conditions like psoriasis and eczema with UV light, to easing SAD with bright light, and promoting skin health with LED therapy Understanding the types, risks, and how to choose a quality device is key.

References

• [1] Cleveland Clinic. (2022-10-28).   Phototherapy (Light Therapy): Uses, Benefits & Risks .
• [2] Wikipedia  Light therapy .
• [3] Verywell Health. (2023-05-12). Phototherapy: Uses, Benefits, and Risks .
• [4] UVA Health  Phototherapy for Skin Conditions .
• [5] Mayo Clinic  Seasonal affective disorder treatment: Choosing a light box .
• [6] Cleveland Clinic. LED Light Therapy: How It Works, Colors, Benefits & Risks .
• [7] Good Housekeeping. (2025-02-25). Best At-Home Red Light Therapy Devices for Glowing Skin .
• [8] PubMed  The dark side of the light: Phototherapy adverse effects .
• [9] PMC  What is the optimal implementation of bright light therapy for seasonal affective disorder (SAD)?
• [10] National Psoriasis Foundation. (2024-02-22). The Light Treatment Effectiveness (LITE) Study Demonstrates that Home Phototherapy may be Considered a First Line Treatment Option for Plaque or Guttate Psoriasis .
• [11] NCBI Bookshelf - StatPearls  Phototherapy .