A Review of Protocols for 308 nm Excimer Laser Phototherapy in Psoriasis

January 2012 | Volume 11 | Issue 1 | Original Article | 92 | Copyright © January 2012

Tejaswi Mudigonda BS, Tushar S. Dabade MD, Steven R. Feldman MD PhD

Center for Dermatology Research, Wake Forest University School of Medicine, Winston-Salem, NC


Background: 308 nm excimer laser phototherapy is efficacious in the treatment of localized psoriasis. Different approaches regarding dose fluency, number of treatments, and maintenance have been utilized, and there is yet to be a consensus on standard protocol.
Objective: To characterize treatment parameters for 308 nm excimer laser phototherapy.
Methods: We performed a PubMed search for studies describing excimer laser treatment protocol with particular attention to dosage determination, dose adjustment, dose fluency, number of treatments, and maintenance.
Results: Seven prospective studies were found describing the excimer efficacy for psoriasis. All studies determined the initial treatment dose using either the minimal erythema dose (MED) or induration. Fluency ranged from 0.5 MED (low) to 16 MED (high); one study demon- strated that medium to high fluencies yielded better improvement in fewer number of treatments. Fluency adjustments during the course of treatment were important to minimize phototherapy-associated side effects. The use of higher fluencies was reported to result in higher occurrences of blistering. One study implemented a maintenance tapering of dose-frequency phase to better manage psoriasis flare-ups.
Conclusion: The 308 nm excimer laser is an effective therapy for psoriasis regardless of the method used to determine initial dosage, dose fluency, or number of treatments. As its usage as a targeted monotherapy increases, future trials should consider evaluating and modifying these parameters to determine the most optimal management of localized psoriasis. Based on our reviewed studies, there is no consensus for a single excimer laser therapy protocol and as a result, patient preferences should continue to be an important consid- eration for phototherapy regimen planning.

J Drugs Dermatol. 2012;11(1):92-97.


Dermatologists are challenged by the various ways to treat localized psoriasis. Regimens include topical cor- ticosteroids, topical retinoids, vitamin D analogs, tar products, and UV phototherapy, whose subtypes include pso- ralen plus ultraviolet A (PUVA), broadband ultraviolet B (BBUVB), and narrowband ultraviolet B (NBUVB). While UV phototherapy is considered to be very effective for extensive psoriasis treat- ment, whole body forms of UV phototherapy are limited by the high number of treatment sessions, the need to frequently go to the hospital/office for treatments, and irradiation of uninvolved skin.1 Although topical therapies permit targeted delivery to af- fected areas only, patients tend to find them time consuming and bothersome.2 Additionally, topicals are less effective in inducing clearance and prolonged remission compared to phototherapy.3
The 308 nm XeCl excimer laser represents one of the latest ad- vancements in the management of localized psoriasis. First used in dermatology in 1997 for treating psoriasis,4 this therapy has shown to be more effective and safer than conventional NBUVB for psoriasis treatment.5-8 The laser has the advantage of being able to focus UVB to specific areas in a user-friendly, efficient man- ner while avoiding exposure to surrounding skin. Furthermore, the excimer laser may be used at a higher fluency, resulting in fewer treatments and lower cumulative doses than NBUVB.9,10
Numerous studies have demonstrated the efficacy of the excimer laser using various treatment strategies; however, standardized clinical protocol or guidelines have not been established. This review characterizes the different elements in 308 nm excimer la- ser phototherapy protocols in order to facilitate evidence-based management of localized psoriasis in the clinical setting.


A review of the literature on 308 nm excimer laser phototherapy was conducted using PubMed. The following search terms were used: phototherapy, localized phototherapy, 308 nm excimer psoriasis, protocol for excimer, phototherapy regimen, and pso- riasis phototherapy. Search terms were used in combinations to create a broad citation list and abstracts were reviewed for relevance to this topic. The inclusion criteria were studies that