Excimer Laser
Excimer laser therapy is a highly targeted form of ultraviolet (UV) light therapy used to treat mild to moderate psoriasis.
Overview
Excimer laser therapy is a highly targeted form of ultraviolet (UV) light therapy used to treat mild to moderate psoriasis. Unlike traditional phototherapy methods that expose the entire body to UV radiation, excimer laser focuses a concentrated beam of ultraviolet B (UVB) light on specific psoriasis lesions, minimizing exposure to healthy skin. It is especially useful for treating small, localized plaques, such as those on the scalp, elbows, knees, and hands, making it a valuable treatment option for patients who do not require full-body phototherapy.
How it works
Excimer laser therapy utilizes 308 nm wavelength UVB light, which is close to the narrowband UVB (NB-UVB) spectrum. This wavelength has been shown to be highly effective in reducing the symptoms of psoriasis by targeting overactive skin cells and modulating the immune response:
Targeted UVB Emission: The excimer laser delivers precise, controlled doses of high-intensity UVB light directly to psoriatic plaques. The focused energy penetrates the skin and induces apoptosis (cell death) of overproducing keratinocytes, which are responsible for the rapid skin cell turnover seen in psoriasis.
Immune Modulation: In addition to slowing down skin cell production, excimer laser therapy reduces the activity of T-cells, a type of immune cell involved in the autoimmune processes that drive psoriasis. This helps decrease inflammation and scaling associated with the condition.
Indications for Use in Psoriasis
Excimer laser therapy is especially beneficial for patients with localized, stubborn psoriasis plaques that are resistant to topical treatments. It is commonly used for:
Plaque Psoriasis: Particularly effective for small, well-defined plaques on areas such as the elbows, knees, and scalp.
Scalp Psoriasis: Due to the precision of the laser, it can target psoriatic lesions on the scalp without affecting surrounding healthy skin or hair.
Palmoplantar Psoriasis: Excimer laser is often employed to treat palmoplantar psoriasis, which affects the hands and feet and can be difficult to treat with other therapies.
Psoriasis in Sensitive Areas: Since excimer laser can be precisely controlled, it is useful for treating psoriasis in sensitive areas such as nails or intertriginous areas (areas where skin touches skin, such as under the breasts or between fingers).
Efficacy
Excimer laser therapy has been shown to be highly effective for localized psoriasis. Research indicates that the 308 nm wavelength used in excimer laser therapy is particularly well-suited for treating psoriasis, leading to:
Rapid Results: Patients often experience significant improvement after just a few sessions, with many reporting a visible reduction in plaque thickness, scaling, and erythema (redness) within 4-10 treatments.
High Clearance Rates: Studies suggest that excimer laser therapy can lead to 80-90% clearance of treated plaques, with some patients achieving complete clearance. The results are particularly encouraging for patients with small, localized plaques.
Fewer Treatment Sessions: Compared to traditional phototherapy methods like NB-UVB, excimer laser requires fewer treatment sessions to achieve the same therapeutic effect due to its high energy and targeted approach. This makes it more convenient for patients with localized psoriasis.
Treatment Process
Excimer laser therapy is administered by a dermatologist or healthcare provider with experience in phototherapy. The treatment process typically involves:
Initial Consultation: Before beginning treatment, the dermatologist evaluates the patient’s psoriasis to determine if excimer laser is appropriate. The size, location, and severity of the plaques are considered.
Targeted Laser Application: During each treatment session, the dermatologist uses a handheld excimer laser device to deliver focused UVB light directly to the psoriasis plaques. The treatment time depends on the size and number of lesions but typically lasts just a few minutes.
Frequency of Sessions: Most patients receive excimer laser treatments twice a week for several weeks. The total number of sessions varies, but patients typically require 6-10 sessions for significant improvement.
Personalized Treatment Plan: The laser’s intensity and exposure time are carefully adjusted based on the patient’s skin type, psoriasis severity, and response to treatment. Higher doses are often used as the treatment progresses to enhance efficacy.
Follow-up and Maintenance: After achieving clearance, patients may require maintenance therapy every few months to prevent flare-ups, especially if their psoriasis recurs in the same locations.
Advantages of Excimer Laser Therapy
Excimer laser therapy offers several advantages over other psoriasis treatments, especially for patients with localized disease:
Targeted Treatment: Unlike full-body phototherapy, excimer laser precisely targets psoriatic plaques, sparing healthy skin from unnecessary UV exposure. This reduces the risk of broad-spectrum UV-related side effects such as premature aging or UV-induced skin cancers.
Fewer Treatments Required: Excimer laser is more efficient than traditional phototherapy, requiring fewer treatment sessions to achieve the same level of improvement, which reduces the overall burden on the patient.
Minimized Risk of Skin Cancer: Since only the affected areas are treated, there is a reduced risk of UV-related skin cancer compared to other phototherapy options, especially in patients with small, localized plaques.
Safe for Sensitive Areas: The laser can be precisely applied to areas that are hard to treat with other therapies, such as the scalp, nails, or intertriginous areas, where traditional phototherapy or systemic treatments may not be practical or safe.
Suitable for Resistant Psoriasis: Excimer laser is highly effective for stubborn plaques that do not respond well to topical treatments, particularly in localized areas where systemic therapies are not necessary.
Side Effects and Risks
Although excimer laser therapy is generally safe, there are some potential side effects and risks associated with its use:
Localized Redness and Burning: The most common side effects are erythema (redness) and burning at the treatment site, similar to a mild sunburn. These effects are usually temporary and subside within a few days.
Blistering and Peeling: In some cases, higher doses of excimer laser can cause blistering, peeling, or crusting of the treated skin. This is more common in patients with fair skin or those with sensitive areas of psoriasis.
Hyperpigmentation: Treated areas may develop temporary hyperpigmentation (darkening of the skin), particularly in patients with darker skin tones. This usually resolves after the treatment is completed.
Risk of Overexposure: Although the laser is precisely targeted, there is still a small risk of overexposure to UV light, especially if higher doses are used too quickly. This can lead to long-term skin damage if not properly managed by a healthcare provider.
Not Suitable for Extensive Psoriasis: Excimer laser is typically reserved for patients with localized plaques. It is not practical for patients with extensive psoriasis covering large portions of the body, as it would require too many sessions to treat effectively.
Comparison to Other Phototherapy Options
Compared to Narrowband UVB (NB-UVB): Excimer laser therapy is more targeted than NB-UVB and is particularly useful for small areas of psoriasis. While NB-UVB treats larger areas of skin, excimer laser focuses exclusively on psoriatic plaques, reducing overall UV exposure.
Compared to PUVA (Psoralen + UVA): Unlike PUVA therapy, which requires a photosensitizing agent (psoralen) and poses a higher risk of skin cancer, excimer laser therapy does not involve any systemic medication and carries a lower risk of long-term side effects.
Compared to Systemic Therapies: Excimer laser therapy is a safer option for patients with mild to moderate psoriasis who do not require systemic treatments like methotrexate or biologics. It offers a targeted solution without the systemic risks associated with these medications.
Summary
Excimer laser therapy is a highly effective and targeted treatment for localized psoriasis, particularly for small, stubborn plaques that do not respond well to topical treatments or other forms of phototherapy. Its ability to precisely target psoriatic lesions while minimizing exposure to healthy skin makes it a safer option for certain patients. However, due to the localized nature of the treatment, it is not suitable for individuals with widespread psoriasis. Patients undergoing excimer laser therapy must work closely with their dermatologist to ensure proper dosing and minimize side effects.