Title: Acute adverse events during PUVA and narrowband UVB phototherapy: a preliminary study to establish base-line rates of adverse events
Abstract: Both photochemotherapy with psoralen (PUVA) and narrowband UVB phototherapy (NB-UVB) are frequently used treatments for a variety of skin conditions. There is little published data on the rate of acute adverse events and the available literature consists mainly of case reports. This retrospective study examined the nature and frequency of acute adverse events occurring with PUVA and NB-UVB therapy. Since 1996 it has been policy in two phototherapy units to record every adverse event reported by patients or noticed by staff, including mild and possibly non treatment-related episodes. The records were evaluated for a 5-year period and the number of acute adverse events was analyzed in relation to the total number of treatments in order to derive an estimate of the rate of adverse events. Mild, painless erythema was regarded as a normal reaction to the treatment. Events were classified into the following categories: Non treatment-related, non-compliance by patients, staff errors, viral infections, symptomatic local or diffuse erythema/burns, localized blisters, induction of polymorphic light eruption, disease flare-up, systemic symptoms (PUVA only). Non treatment-related adverse events were excluded from further analysis. Adverse events resulting from patient's mistakes, such as changes in underwear, hairstyles or positions during the treatments were classified as non-compliance. Of 271 treatment-related acute adverse events 125 (0.5%) occurred with NB-UVB therapy during 24, 241 treatments; of which 15 (0.06%) episodes were classified as 'serious' if patients presented with marked painful erythema, edema and/or blisters. During 17, 502 treatments with PUVA, 146 (0.8%) treatment-related acute adverse events were recorded. Of these, 22 (0.13%) episodes were considered 'serious' which was twice as frequent compared to NB-UVB therapy. The rate of erythema/burns (0.33%/0.19%) and blisters (0.12%/0.03%) were higher in the patient groups receiving PUVA compared to NB-UVB therapy. In contrast, viral infections were more common with NB-UVB therapy (0.07%/0.03%). Rates for staff errors, patient non-compliance, polymorphic light eruption and disease flare-up showed similar results with both treatment modalities. In conclusion, acute adverse events for both PUVA and NB-UVB therapy were considered low in both units but the occurrence of 'serious' events emphasizes the need for robust treatment procedures, which facilitate the safe and effective use of phototherapy.