Efficacy of ultraviolet A1 phototherapy for inflammatory, sclerotic and neoplastic dermatological diseases: A 10-year tertiary referral center experience.

Background: Ultraviolet (UV) A1 phototherapy is considered a beneficial treatment for various inflammatory, sclerotic, malignant, and other skin conditions. However, the available data regarding its efficacy for different indications, the potential side effects, and the recommended treatment protocols are sparse.
Objectives: To assess the efficacy of UVA1 phototherapy and identify correlation between different indications and treatment protocols to response rates.
Methods: We performed a retrospective study of a cohort of 335 patients treated with UVA1 phototherapy at the Department of Dermatology at Hadassah Medical Center, Jerusalem, Israel, between 2008 and 2018.
Results: The study population included 163 patients with inflammatory diseases (mainly atopic dermatitis and other types of eczema), 67 patients with sclerotic diseases (morphea and graft versus host disease), nine patients with neoplastic diseases (cutaneous T cell lymphoma), and 188 patients with other cutaneous disorders. Response rates ranged between 85% and 89% across indications, without differences in response rates among the indication groups (p = .941). In a multivariant logistic regression model, increased number of treatments and higher maximal dosages were associated with response to treatment (p < .001). Using ROC analysis, a cut-off of 8 UVA1 phototherapy treatments was chosen as predictive for beneficial response (86.4% sensitivity, 78% specificity). A cut-off of 40 J/cm ² was chosen as an optimal maximal dosage for differentiating between responders and non-responders (51.1% sensitivity, 83.1% specificity).
Conclusions: UVA1 phototherapy is an effective treatment for a variety of skin conditions. In most patients, at least eight treatments of a medium-high dosage are required for clinical response.
(© 2022 The Authors. Photodermatology, Photoimmunology & Photomedicine published by John Wiley & Sons Ltd.)