Excimer Laser Phototherapy Outcomes in the Treatment of Psoriasis

Not Applicable

Terminated

Brief Summary: The purpose of this study is to determine the best dosing strategy when using Excimer Laser to treat plaque-type psoriasis. In this study, half of the body's psoriasis will be treated with a new dosing strategy, and the other half will be treated with the conventional method. We hope to show that the new dosing strategy will result in faster improvement of psoriasis.

Detailed Description: This is a randomized, assessor-blinded clinical trial to determine whether a novel plaque-based dosimetry strategy can improve the speed of response to excimer laser treatment in patients with plaque psoriasis. Each patient will receive plaque-based dosing on one side of the body and conventional dosing on the contralateral side. This design is based on the assumption that psoriasis usually affects patients in a symmetric distribution (e.g., knees and elbows) and the effect of excimer laser phototherapy is limited to the treated plaque. The side of the body treated with plaque-based dosimetry will be assigned using a table of random numbers. The assessor will be blinded to the treatment group. Each patient will be treated 1-2 times per week at the discretion of the investigator for a maximum of 10 treatments.

Recruitment & Eligibility

Inclusion Criteria

Diagnosis of chronic plaque psoriasis for at least 6 months
Age ≥ 18 years
Body surface area affected ≤ 10 percent
Presence of at least one pair of bilateral target lesions with an area of at least 20 cm2 per target lesion. The bilateral target lesions must be present in the same category of anatomical region (e.g., bilateral lower extremities, bilateral upper extremities or bilateral trunk).

Exclusion Criteria

active or past history of erythrodermic psoriasis, guttate psoriasis, or pustular psoriasis
history of photosensitivity disorder
history of malignant melanoma
active, invasive non-melanoma skin carcinoma
Fitzpatrick Skin Type I
Subject has received ultraviolet B phototherapy or any topical anti-psoriatic therapy within two weeks prior to starting the study.
Subject has received systemic or topical psoralen-ultraviolet A photochemotherapy within four weeks prior to starting the study.
Subject has received biologic therapy within three months of starting the study.

Arm && Interventions

Group	Intervention	Description
Conventional Dosing	Excimer laser phototherapy	Patients psoriasis to be treated with Excimer laser phototherapy based on conventional dosing guidelines. These guidelines determine the starting dose based on plaque thickness and the skin type of the patient. Patients will also be evaluated for psoriasis plaque response to test doses. The best dose will be selected from a test matrix of doses.
Plaque based dosing	Excimer laser phototherapy	Patients will also be evaluated for psoriasis plaque response to test doses. The best dose will be selected from a test matrix of doses.

Primary Outcome Measures

Name	Time	Method
Modified Psoriasis Area Severity Index	10 weeks	The Modified Psoriasis Area Severity Index is a scale that grades psoriasis based on thickness, redness, scaling, and area involvement.

Secondary Outcome Measures