Excimer Laser Therapy for Hairline Psoriasis: A Useful Addition to the Scalp Psoriasis Treatment Algorithm

Jillian W. Wong, BA^1,2; Faranak Kamangar, BSc²; Tien V. Nguyen, BA²; John Y.M. Koo, MD²

¹University of Utah School of Medicine, Salt Lake City, UT, USA
²Department of Dermatology, Psoriasis and Skin Treatment Center, University of California, San Francisco, San Francisco, CA, USA

Conflicts of Interest : Ms. Wong, Ms. Kamangar, and Mr. Nguyen have no financial conflicts of interest to report. Dr. Koo has the following
conflicts of interest: Abbott, Amgen, Leo, Galderma, GlaxoSmithKlein, Janssen, Novartis, PhotoMedex, Pfizer, and Teikoku.
ABSTRACT

Psoriasis is a chronic, inflammatory skin condition with negative impacts both physical and psychological. Scalp psoriasis, especially around the hairline, can cause significant impairment in quality of life due to its visibility. Options for treatment of facial psoriasis, including hairline involvement, are the use of low potency topical steroids, calcineurin inhibitors, and vitamin D analogues. Though the use of excimer laser for scalp psoriasis has been reported, there are no cases or studies specifically examining excimer laser phototherapy for the treatment of hairline psoriasis. We present a case of rapid improvement of hairline psoriasis using a regimen of 308 nm excimer laser with clobetasol spray and recommend an algorithm for the optimal treatment of scalp psoriasis utilizing currently available antipsoriatic therapies.

Key Words:
topical corticosteroid, excimer laser, phototherapy, scalp psoriasis

Introduction

Psoriasis is an inflammatory skin disease affecting approximately 2.6% of the U.S. population.¹ Psoriasis tends to remain stable throughout the patient’s lifetime or become gradually more widespread. It is associated with a high degree of morbidity, as well as having a negative impact on the lives of patients physically, psychologically, socially, and occupationally.^2,3 As it is a chronic condition, psoriasis often requires lifelong treatment.

Patients suffering from psoriasis have relatively high rates of depression and often report stigmatization, embarrassment, and self-consciousness.⁴ Plaques along the hairline and retroauricular regions are visible and resistant to therapy. Treatment of scalp psoriasis with laser has been reported, but this modality presents challenges due to the difficulty of penetration of photons through hair.⁵ Hence, such a limitation may discourage the use of excimer laser for scalp psoriasis. It must be noted, however, that because the forehead, hairline, and retroauricular areas are not entirely covered by hair, treatment with laser is a clearly viable option.

Targeted ultraviolet B (UVB) excimer laser phototherapy is one of the most cutting-edge advances in phototherapy. The xenon chloride laser produces a 308 nanometer (nm) monochromatic beam of light that is efficacious for the treatment of psoriasis.⁶ In contrast to traditional phototherapy, the UVB laser treats targeted areas while sparing the non-involved skin. Psoriatic plaques can tolerate increased dosimetry compared with non-involved skin, and a supra-erythmogenic dose (multiple times above the minimal erythema dose [MED]) can be delivered, resulting in faster clearance than with traditional UVB phototherapy.^6,7 We first present a case of rapid improvement and maintenance of hairline psoriasis treated with 308 nm excimer laser and clobetasol spray, followed by a discussion of current treatment options, and, finally, offer a recommended algorithm for the treatment of scalp psoriasis.

Case

A 68-year old Filipino female presented with a 16-year history of generalized plaque-type psoriasis. She reported that the most distressing region covered with psoriasis was her hairline because it caused severe pruritus and visible disfigurement. The patient failed past treatment on acitretin and topical therapies, including clobetasol ointment, fluocinonide 0.05% solution, calcipotriene ointment, and fluocinolone acetonide 0.01% oil. She had a past medical history of thyroid cancer with a thyroidectomy, stroke, and coronary artery bypass graft. She had no history of sun or other light sensitivity and no history of skin cancer. Her current medications included levothyroxine, metoprolol, warfarin, atorvastatin, and calcium and vitamin D supplements. She was not on any psoriasis therapies at the time of presentation.

On physical examination, there were thick, well-demarcated plaques of psoriasis with silvery scale over the lower and upper extremities bilaterally, back, abdomen, buttocks, scalp, and hairline, including over the forehead, retroauricular, and occipital area.

As the patient had a past history of cancer, she was not placed on immunosuppressive therapy. Topical therapy alone had not been sufficient for treating her psoriasis. Therefore, the patient was started on twice weekly excimer laser therapy (Photomedex XTRAC® Velocity) in conjunction with clobetasol propionate 0.05% (Clobex®) spray twice daily.

The patient was started on a dose of 400 millijoules per square centimeter (mJ/cm²) for laser therapy, which was increased to 500 mJ/cm² following her first treatment. After 2 weeks of therapy, with a total of 4 excimer laser treatments at a dose of 500 mJ/cm² and use of clobetasol spray to affected areas, she demonstrated marked improvement in hairline psoriasis. As the patient responded well to treatment without side effects or irritation, her dose was gradually increased to 666 mJ/cm². After 5 weeks of therapy (receiving a total of 9 laser treatments and using clobetasol spray twice daily), her hairline psoriasis completely cleared. The patient did not experience any side effects from laser therapy, such as blistering, burning, hyperpigmentation, or erythema. After 3 months without any subsequent therapy, the hairline psoriasis had not returned.

Figure 1: Algorithm for scalp psoriasis treatment Feldman SR, Koo JYM, Lebwohl MG, et al. The psoriasis and psoriatic arthritis pocket guide: treatment algorithms and management options. 2nd ed. 2005, p.76. National Psoriasis Foundation.12 Modified with permission.

Discussion

Phototherapy can be an effective treatment for generalized plaque psoriasis. However, one major limitation to the aggressiveness of therapy is the MED, which is the lowest dose that causes minimal erythema in non-psoriatic skin.⁷ The excimer laser overcomes the barrier of MED, which limits the efficacy of traditional phototherapy. The process by which this is achieved is the excimer laser only irradiates psoriatic plaques that typically require many times more light energy than MED when compared to traditional phototherapy. Thus, the excimer laser provides greater capacity for aggressive therapy, resulting in increased efficacy and significantly reduced number of treatments needed for disease improvement.^7-9

The medical literature provides a limited number of studies that have been performed for the specific treatment of hairline psoriasis.¹⁰ The Copenhagen Psoriasis Working Group recommended that the first-line treatment of facial psoriasis, including hairline involvement, should be low potency topical corticosteroids, calcineurin inhibitors, and vitamin D3 analogues.¹¹ However, for general scalp psoriasis, multiple studies have been performed. For mild disease, topical therapies are considered first-line treatments. Topical therapies include gentle care with medicated shampoos, steroids, salicylic acid, tars, calcipotriene/calcipotriol, tazarotene, anthralin, and various combinations of topical agents.¹² In addition, two 52-week studies demonstrated efficacy and safety of calcipotriol/betamethasone diproprionate gel (Xamiol®, Taclonex® scalp suspension) for scalp psoriasis.¹³ More recently, a multicenter, randomized, double-blind study of 81 moderate-to-severe psoriasis patients with scalp involvement evaluated the efficacy and safety of clobetasol spray.¹⁴ Forty-one patients applied clobetasol spray and 40 applied a control vehicle spray twice daily for up to 4 weeks. The study found that 85% (35/41) of the patients using clobetasol spray compared to 13% (5/40) of the control group were assessed as “cleared” or “almost cleared” as measured by the Global Severity Score (GSS).¹⁴

For severe or recalcitrant scalp psoriasis, systemic therapy is recommended, including acitretin, adalimumab, cyclosporine, etanercept, infliximab, and methotrexate.¹² A recent randomized, placebo-controlled study of 124 patients with stable plaque psoriasis and significant scalp psoriasis evaluated the efficacy and safety of etanercept.¹⁵ Sixty-two patients received etanercept 50 mg twice weekly for 12 weeks, followed by etanercept 50 mg once weekly and placebo once weekly. The remaining 62 patients received placebo twice weekly for 12 weeks, followed by etanercept 50 mg twice weekly for 12 weeks. The study found that etanercept was effective and well-tolerated for scalp psoriasis, showing a statistically significant difference in psoriasis scalp severity index (PSSI) between the experimental and control groups. At week 12, 86% in the experimental group achieved 75% improvement in PSSI in contrast to 11% in the control group.¹⁵

Despite concern that the efficacy of excimer laser may be limited by hair preventing maximal penetration of photons, two studies have shown improvement of scalp psoriasis with excimer laser. In an open comparative study of 13 patients with scalp psoriasis, patients were treated with a 308 nm excimer laser in conjunction with a hair blower to part the obstructed hair twice weekly for up to 15 weeks.¹⁶ Initial dosage was based on the MED, and subsequent doses were increased by increments of up to 20%. A statistically significant difference in mean decrease in modified Psoriasis Area and Severity Index (PASI) scores between the treated and control sites was found, and scores were 4 and 2.61 respectively.16 A retrospective study was performed on 35 patients with scalp psoriasis, who were treated by excimer laser using manual separation of the hair to increase exposure of the laser to the scalp.¹⁷ One-half of the scalp was treated, and the other half remained untreated to serve as a control. The results showed that 49% of the patients cleared >95% and 45% of patients cleared 50-95%.¹⁷ However, no studies have examined the use of excimer laser for the specific treatment of hairline psoriasis.

Based on our review of scalp psoriasis treatments and our experience with the excimer laser, we propose an updated algorithm for the treatment of scalp psoriasis, introducing excimer laser as part of the treatment algorithm (Figure 1). For mild scalp psoriasis, the first-line therapy remains topical treatments. However, when psoriasis is resistant to topical therapies or for severe scalp involvement, the combination of excimer laser with topical steroid (i.e., clobetasol spray) could be considered as a viable therapeutic option, as illustrated in our case and in two current studies using excimer laser alone.^16,17 Prior to initiating systemics that carry greater risks to patients, the use of the excimer laser may be an efficacious option for treating recalcitrant plaques along the hairline.

Conclusion

Our case and discussion demonstrates the use of excimer laser in conjunction with topical treatment as an effective and safe method for treating scalp psoriasis. One major limitation of the presented case is that there is a lack of a control arm and, therefore, it is difficult to predict whether the majority of the improvement in psoriasis was attributable to the excimer laser or to clobetasol spray. The clobetasol spray alone may have induced the significant improvements in psoriasis, as the patient had not used clobetasol spray in the past. Furthermore, a study by Sofen et al. showed 85% clearance of psoriasis with clobetasol spray alone.¹⁴ Therefore, the proposed update and addition to the scalp psoriasis treatment algorithm requires more substantiation through a study in which there is a controlled arm, such as comparing the application of clobetasol spray alone to clobetasol spray in conjunction with excimer laser therapy.

Nevertheless, when scalp psoriasis cannot be adequately controlled with topical therapy, the excimer laser can be used effectively to treat hairline plaques, visible lesions that can cause significant psychosocial distress to affected patients. For general scalp psoriasis treatment, clinicians may consider using excimer laser in combination with a topical steroid when topical agents alone do not achieve adequate disease control. This combined therapeutic method may also be considered prior to initiating systemic therapy for severe or intractable cases. Further studies should be performed to establish the safety and efficacy of excimer laser in the treatment of hairline psoriasis. In the future, this novel approach has the potential to become more widely used in clinical dermatology practices.

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