What is the role of Ultraviolet A-1 (UVA-1) in the treatment of keloids and hypertrophic scars?

Updated: May 29, 2020
  • Author: Brian Berman, MD, PhD; Chief Editor: Dirk M Elston, MD  more...
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UVA-1 (340-400 nm) has been reported as an effective treatment for morphea and systemic sclerosis through induction of collagenase I (matrix metalloproteinase I) produced by fibroblasts. Asawanonda et al reported clinical improvement in one keloid in addition to the histological reappearance of normal-looking collagen and elastic fibers, while others have not reported as good clinical results. [105]

Animal models have shown a significant decrease in dermal thickness and collagen content in scars irradiated postsurgically with UVA-1 at 110 J/cm2. UVA-1 exposure to hypertropic scars in rabbits after epithelialization may lead to softening of the scar, thinning of the skin, and a decrease in collagen content. However, immediate irradiation with UVA-1 after wounding could not prevent the development of hypertrophic scarring in rabbits. [106]

Two German studies have evaluated the efficacy of UVA-1 irradiation for the treatment of skin conditions with altered dermal matrix, including keloids, scleroderma, scars, granuloma annulare, and acne keloidalis nuchae. The studies are complete, but results are not yet published. [107, 108]

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