Phototherapy, also known as light therapy, is a well-established and effective treatment option for moderate to severe psoriasis. It uses controlled exposure to ultraviolet (UV) light to slow down the rapid skin cell growth associated with the condition. Medical professionals often recommend phototherapy when topical medications are not sufficient or when psoriasis covers large areas of the body.

The most common form of phototherapy is narrowband UVB therapy. This method uses a specific wavelength of ultraviolet light that has been proven effective in treating psoriasis while minimizing side effects. Patients usually undergo treatments two to three times a week, and improvement can typically be seen after several weeks. The therapy helps reduce inflammation, slow cell turnover, and improve the appearance of plaques.

Another option is broadband UVB, which has been used for decades. While effective, it is less targeted compared to narrowband UVB and is often considered when narrowband options are not available. UVA light combined with a medication called psoralen (known as PUVA therapy) is another approach used for more severe cases. PUVA therapy involves taking psoralen orally or applying it topically to increase the skin's sensitivity to UVA light. This method can be highly effective but requires careful monitoring due to potential side effects.

Excimer laser therapy is a more advanced form of phototherapy that targets small, localized plaques. It uses a concentrated beam of light, allowing doctors to deliver high doses of UV light to specific areas without exposing surrounding skin. This is especially beneficial for psoriasis on the scalp, knees, or elbows.

While phototherapy can be very effective, it requires consistency and commitment. Patients often need numerous sessions before significant improvement occurs, and maintenance therapy may be necessary to prevent flare-ups. Phototherapy is typically administered under medical supervision to ensure proper dosage and minimize risks such as sunburn-like reactions.

In addition to medical settings, some individuals use controlled home phototherapy units. These devices allow for convenient treatment but must be used exactly as prescribed to avoid complications. Not everyone is a candidate for phototherapy, especially individuals with photosensitive conditions or a history of skin cancer.

Despite these considerations, phototherapy remains a powerful tool in psoriasis management. It is non-invasive, drug-free, and has a long-standing track record of success. For many people, light therapy offers a safe and effective pathway toward clearer, healthier skin.