Four cases of intralesional blisters arising during TL-01 UVB phototherapy for chronic plaque psoriasis

摘要

To the Editor, We read with interest the recent article by Fahy et at. (1) describing four cases of intraplaque blistering during TL01-UVB phototherapy. This is a rare phenomenon which we too have observed in our phototherapy department which treats around 6000 patients per year. We present four patients with chronic plaque psoriasis attending for TL01-UVB between 2002 and 2015 who experienced transient intralesional blisters during their thrice weekly treatment to add to the limited literature. All were Fitzpatrick skin type I or II and underwent minimal erythema dose (MED) testing with treatment commenced at 70 of this dose. Our first patient, a 27-year-old female, developed blisters within plaques on her right arm after 4th dose at 674 mj/cm2 with the surrounding skin being unaffected. This was her first course of phototherapy. Treatment was suspended for 7 days during which blistering resolved and was restarted at the previous dose with increasing dose increments to 2500 mj/cm2. No blistering recurred. A 35-year-old female who had three previous TL01 UVB courses and a course of PUVA developed intraplaque blisters, sparing surrounding skin, on both arms and right thigh after 16th dose at 2500 mj/cm2 (Fig. 1). Autoimmune screen; blood, faeces and urine porphyrins; and herpes simplex PCR swabs were negative. Treatment was held for 7 days and restarted at 50 of the last dose with increasing 20 increments. Blisters cleared with no recurrence.