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.
Keywords: PUVA; UVA1; UVB; granuloma annulare; photodynamic therapy; phototherapy.
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