Phototherapy for Psoriasis - An Overview

What Is Phototherapy?

For most people, over-the-counter medications are sufficient to address psoriasis; others may need phototherapy, especially if the skin remains itchy, scaly, and red. Phototherapy, also known as light therapy, is one of the most effective treatments for psoriasis. The procedure involves exposing the skin to regulated amounts of ultraviolet (UV) radiation. Healthcare professionals often prescribe phototherapy with other treatments when conventional therapies fail to provide alleviation and are particularly useful for treating moderate to severe psoriasis covering large areas of the body. In addition to psoriasis (an autoinflammatory skin condition), phototherapy is also performed for other skin disorders, such as lichen planus, atopic dermatitis (eczema), vitiligo, and cutaneous T-cell lymphoma.

What Are the Potential Side Effects of Phototherapy?

Phototherapy is performed in a healthcare professional's office under controlled conditions. However, despite this precaution, people can still experience side effects. Possible side effects of phototherapy include:

• A stinging or itching sensation.

• Sores and redness on the skin.

• Signs of premature skin aging include loose skin, dark spots, and leathery skin.

• Mild sunburn is generally not severe and often resolves by changing the ultraviolet (UV) dosage.

• Possibility of cold sores in people prone to them.

• Blisters.

• A higher risk of skin cancer.

Why Is Phototherapy Prescribed for Psoriasis?

Phototherapy is seldom used on its own. Instead, it is generally suggested when topical medications, such as corticosteroids, cannot provide relief. This is because it helps improve the effects of topical therapies. For moderate to severe psoriasis, phototherapy is used with oral or injectable drugs to temper inflammation from within. Phototherapy treatment can:

• Suppress an overly active immune system.

• Slow and rapidly growing skin cells.

• Reduce or eliminate the itching.

• Reduce inflammation and allow healing.

What Are the Different Types of Phototherapy Procedures?

The various types of phototherapy procedures are listed below:

1. Ultraviolet Light B (UVB):

Ultraviolet light B (UVB) is present in natural sunlight and is an effective psoriasis treatment. UVB goes into the skin and delays the growth of affected skin cells. UVB treatment includes UVB phototherapy, in-office or home UVB phototherapy, or excimer laser. This treatment involves exposing the skin to an artificial UVB light source regularly for a set time. There are typically two types of UVB treatment: narrow-band and broad-band. Narrow-band UVB light bulbs emit a narrow range of ultraviolet light.

• Narrow-Band UVB: It is the most common light therapy. It can clear psoriasis symptoms faster and produce more prolonged remissions. Narrow-band UVB light may need fewer treatments per week.

• Broad-Band UVB: This type of phototherapy is the oldest form of light therapy for psoriasis and uses a wider wavelength than narrow-band therapy. Broad-band light therapy is less effective than narrow-band therapy and is more likely to cause side effects. Therefore, it should be done for cases where narrow-band is not a treatment option.

2. Psoralen + Ultraviolet Light A (UVA) (PUVA):

• Ultraviolet light A (UVA) is relatively inefficient for psoriasis treatment unless used with light-sensitizing agents known as psoralens. This process is called PUVA. It delays excessive skin cell growth and can alleviate psoriasis symptoms for varying periods.

• There are three central administration ways for PUVA; topical cream, lotion, or gel, mixed with bathwater, or as a pill.

• PUVA treatment is most effective for guttate psoriasis, stable plaque psoriasis, and psoriasis of the palms and soles.

• PUVA removes psoriasis symptoms effectively with long-lasting results. However, using this therapy for a long time can raise the risk of skin cancer. So it is typically only recommended for severe cases or other treatments that have not worked.

• This treatment also has adverse effects such as exhaustion, nausea, headaches, burning, and itching.

• Because psoralen makes the body extra sensitive to light, one should protect the skin and eyes by taking measures such as wearing glasses that block ultraviolet light and wearing sunscreen after treatment.

3. Sunlight:

• Although UVB and UVA are found in sunlight, UVB works best for treating psoriasis. This is because UVB from the sun functions similarly to UVB in phototherapy treatments. However, using sunlight is not prescribed for everyone with psoriasis.

• In addition, sunlight is not as effective for treating psoriasis as prescription phototherapy. Too many rays from the sun can worsen the psoriasis symptoms and raise the chances of getting skin cancer.

• Some topical drugs, such as Tazarotene and coal tar, can increase the risk of sunburn.

• People using PUVA or other light therapy should restrict or avoid exposure to natural sunlight unless directed by a health care professional.

• Speak to a health care professional to determine whether or not treating with sunlight is right.

4. Lasers:

• Lasers use highly focused beams of light to target the skin affected with psoriasis patches, reducing side effects and lowering the risk of skin cancer.

• This requires fewer treatments compared with other types of phototherapy.

• The excimer laser releases a high-intensity beam of ultraviolet B. It can target mild-to-moderate psoriasis-affected skin areas. Research suggests it is a particularly effective treatment for scalp psoriasis. However, there is a lack of long-term data to indicate how long improvements will last following excimer therapy. This treatment is done twice weekly in a healthcare professional's office for four to five weeks.

• Pulsed dye laser (PDLs) is also used to treat psoriasis. PDLs utilize a liquid with an organic dye to make a laser that produces gentle bursts of focused light beam onto carefully targeted skin areas. The heat clears away damaged blood vessels but maintains the surrounding skin as safe as possible.

• Side effects from laser treatments are generally minimal, but they can hurt a bit for some people. For example, people who get laser therapies may experience bruising, sunburns, and scarring at the treated sites.

5. Grenz Rays:

• This is a less commonly used approach. Healthcare professionals advise this treatment with superficial X-ray machines to project a form of soft X-rays that work in a way similar to UV light.

6. Photodynamic Therapy:

• Though uncommon, healthcare professionals may suggest photodynamic therapy to treat psoriasis.

• This therapy uses special medicines that boost the effects of a light source.

• Unfortunately, side effects of burned skin can limit this approach's effectiveness in treating psoriasis.

Can Anyone With Psoriasis Use Phototherapy?

While healthcare professionals prescribe phototherapy for many people, it is not recommended for people who have:

• Medical problems that make them more susceptible to developing skin cancers, like Gorlin syndrome (nevoid basal cell carcinoma syndrome) or xeroderma pigmentosum (extreme sensitivity to ultraviolet (UV) rays).

• Melanoma or any other type of skin cancer.

• Medical conditions that make them sensitive to UV light, such as lupus (an autoimmune condition) or porphyria (a condition of the skin and nervous system).

• Medications such as antibiotics, antifungals, and diuretics (water pills) make them more sensitive to UV light.

Conclusion

Phototherapy is one of the most effective psoriasis treatments that involves exposing the skin to ultraviolet light regularly and under medical supervision. Besides reducing the pain and itchiness of the condition, it can help people manage their condition and improve their quality of life. However, to safely treat phototherapy, it is best to speak to a healthcare professional about a suitable treatment option.