PD18 Ultraviolet A1 phototherapy is an effective treatment for fibrotic skin conditions and granuloma annulare: a retrospective case series of 67 patients treated at a tertiary photodermatology unit

Abstract

Ultraviolet A1 (UVA1) phototherapy (340–400 nm) is an established therapy in the management of fibrotic skin conditions and some inflammatory dermatoses. We present a retrospective case series of our experience with UVA1 phototherapy. The aim was to evaluate the conditions treated, dose requirements, response rates, adverse effects and relapse rates for various dermatoses treated with UVA1 phototherapy at a tertiary referral centre. We conducted a retrospective case series of all patients attending the UVA1 phototherapy clinic between January 2025 and December 2025. Data were collected from the electronic patient records. Treatments were administered using a Sellamed 24000 whole-body UVA1 unit. Treatment responses were graded using a previously described UVA1 seven-point scale and classified as ‘beneficial’ (grades 4–6) or ‘not beneficial’ (grades 0–3). In total, 67 patients who had completed at least one UVA1 phototherapy course were included; 77% were female and the mean age was 54.1 years (SD 17.3). The most common indication was morphoea (n = 42, 63%), followed by extragenital lichen sclerosus (n = 9, 13%) and granuloma annulare (n = 6, 9%). The mean number of sessions needed per patient was 52.7 (SD 50.3), with a mean maximum single dose of 61 J cm−2. Overall, 86% of patients achieved a beneficial outcome. Beneficial response rates were highest in plaque and linear morphoea, diffuse cutaneous scleroderma, granuloma annulare, eosinophilic fasciitis and systemic sclerosis. One-half (51%) of patients required repeat courses. Adverse events occurred in 24 (36%) patients, predominantly grade 2 erythema. No patients discontinued treatment due to adverse effects. At a mean follow-up of 4.1 years, the overall relapse rate was 23%. UVA1 phototherapy was a well-tolerated and effective treatment in 86% of patients. Linear morphoea, plaque morphoea, granuloma annulare, systemic sclerosis and eosinophilic fasciitis demonstrated the highest response rates. This highlights the importance of UVA1 phototherapy in the management of fibrotic skin conditions, particularly those resistant to conventional treatment.