Phototherapy in Psoriasis: A Review of Mechanisms of Action

This study found that narrowband UVB light therapy reduced the severity score of atopic dermatitis, a common inflammatory skin disease, by at least 50% for all subjects. The study then looked at the mechanisms of action and found that UVB light therapy suppressed inflammatory Th2 and T22 immune cells and normalized expression of skin barrier proteins to reduce skin thickening due to overactive keratinocytes.

This randomized controlled trial compared narrowband UVB light therapy and red light therapy, each used in combination with 2% erythromycin cream, for the treatment of acne. They found that narrowband UVB therapy demonstrated greater efficacy than red light therapy in reducing acne lesion counts and improving overall acne severity.

Pruritus, severe itching of the skin, is a common, irritating symptom associated with chronic kidney disease. This study compared the use of narrowband UV light therapy to the use of medical moisturizers in hemodialysis patients and found that UVB light therapy was more effective at lowering itch score in this patient population. The UVB treatment group saw a statistically reduction of itch-score of more than half from baseline levels.