The role of excimer light in dermatology: a review

Excimer light is a subtype of NB-UVB that emits a 308 nm wavelength, and can provide targeted phototherapy treatment. The absorption of 308 nm light by skin cells leads to therapeutic response in various common and ultraviolet-responsive skin diseases, such as psoriasis and vitiligo, and photo-resistant skin diseases such as prurigo nodularis, localized scleroderma, genital lichen sclerosis, and granuloma annulare, cutaneous T-cell lymphomas, among others. Excimer light has few adverse reactions and overall is well tolerated by patients, furthermore, it can be performed in places that are difficult to access. This article aims to explain the therapeutic bases and applications of excimer light in current dermatology.

Light- and laser-based treatments for granuloma annulare: A systematic review

BACKGROUND

Granuloma annulare (GA) is challenging to treat, especially when generalized. A systematic review to support the use of light- and laser-based treatments for GA is lacking.

METHODS

We performed a systematic review by searching Cochrane, MEDLINE, and Embase. Title, abstract, full-text screening, and data extraction were done in duplicate. Quality appraisal was performed using the Joanna Briggs Institute critical appraisal tool for case series.

RESULTS

Thirty-one case series met the inclusion criteria, representing a total of 336 patients. Overall, psoralen ultraviolet light A (PUVA) showed the greatest frequency of cases with complete response (59%, n = 77/131), followed by photodynamic therapy (PDT) (52%, n = 13/25), ultraviolet light B (UVB)/narrowband UVB (nbUVB)/excimer laser (40%, n = 19/47), UVA1 (31%, n = 27/86), and lasers (29%, n = 8/28). Overall across treatment modalities, higher response rates were seen in localized GA compared to generalized GA.

CONCLUSIONS

The body of evidence for light- and laser-based treatment of GA is sparse. Our results suggest that PUVA has a high clearance rate for GA but its use may be limited by concerns of carcinogenesis. Although PDT has the second highest clearance rate, adverse effects, small sample sizes, impractical treatment delivery (especially with generalized disease), and long-term concerns of carcinogenesis may limit its use. Although UVB/nbUVB/excimer laser appeared slightly less effective than other light therapies, we recommend UVB/nbUVB/excimer laser therapy as a first-line treatment for patients with generalized GA given wider availability and a favorable long-term safety profile.

A Monocentric, Retrospective Analysis of 61 Patients with Generalized Granuloma Annulare

BACKGROUND

Granuloma annulare is a chronic noninfectious granulomatous skin condition with variable clinical presentations. Generalized granuloma annulare, defined as widespread disease with >10 skin lesions, accounts for 15% of all cases. Numerous associated diseases have been controversially discussed, most importantly diabetes mellitus, dyslipidemia, thyroid disease, malignancy and systemic infections.

OBJECTIVES

The objective of our study is to describe disease characteristics, treatment outcome and associated diseases in patients treated at the Department of Dermatology of the University Hospital Zurich during the last 20 years.

METHODS

The hospital database was searched for patients with generalized granuloma annulare in the last 20 years (January 1, 1998, to December 31, 2017). Overall, 61 patients, 14 males and 47 females, were included in our study. The mean age was 58 years at first consultation. The diagnosis was verified clinically and histologically.

RESULTS

Generalized granuloma annulare occurred at a mean age of 55 years, more commonly in females. Pruritus was absent in 51% of all patients. Metabolic diseases including diabetes mellitus, hypercholesterinemia and hypertriglyceridemia were present in 10.5, 8.2 and 4.9%, respectively. Thyroid disease was present in 9.8% and malignant disease in 23%, including colorectal cancer, lymphoproliferative disease, squamous cell carcinoma of the esophagus, basal cell carcinoma and gynecological malignancy. Therapy was initiated in 92%, while second- and third-line therapy was performed in 70 and 39%, respectively. Benefit during therapy (e.g., full and partial remission) was achieved in 39.3% during first-line, in 39.4% during second-line and in 33.8% during third-line treatment. Topical corticosteroids were the most commonly prescribed treatment, mostly leading to stable disease (46.6%). Combined full and partial remission occurred in a large proportion of patients receiving UVA1 (45%), PUVA (63.6%) and intralesional triamcinolone acetonide (100%).

CONCLUSIONS

Generalized granuloma annulare is a mostly asymptomatic and benign disease with a strong tendency for treatment resistance. We suggest to screen all patients for dyslipidemia, thyroid disease and malignant disease. While randomized trials are needed, we suggest topical corticosteroids as the first-line treatment, intralesional triamcinolone acetonide for persistent solitary lesions and, if further treatment is needed, UVA1 or PUVA.

Beyond the Booth: Excimer Laser for Cutaneous Conditions

The excimer laser has emerged as an efficacious treatment modality for many dermatologic diseases. The excimer laser is an alternative to standard narrowband ultraviolet B (NBUVB) phototherapy treatment in patients with limited disease. In comparison to standard NBUVB, the excimer laser requires fewer treatment sessions, has reduced treatment duration, requires a lower cumulative UVB dose, and limits UVB exposure to lesional skin. This review addresses the mechanism, safety, application, and efficacy of the excimer laser for the treatment of these conditions.

Granuloma Annulare: A Focused Review of Therapeutic Options

Granuloma annulare (GA) is a benign inflammatory disease associated with many conditions such as malignancy, trauma, thyroid disease, diabetes mellitus, and HIV infection. Common clinical subtypes include localized GA, generalized GA, subcutaneous GA, perforating GA, and patch GA. There exists an abundance of literature on GA, yet we know relatively little about its exact etiology and even less about its treatment. The paucity of conclusive data on effective treatment options is largely because the majority of published studies are limited to small case reports, case series, and retrospective studies. As such, there does not yet exist a gold standard of care to guide clinical management. Depending on the clinical subtype, the clinical prognosis for GA can vary. The localized variant generally self-resolves within 2 years without treatment, whereas the generalized form is more chronic and less responsive to treatment. This focused up-to-date review serves to summarize the latest therapeutic options available for GA.