title: Successful photopatch testing with ketoprofen using one-hour occlusion.
abstract: The standard procedure for photopatch testing includes 24-h occlusion of the allergen, followed by irradiation at 5 J/cm2 ultraviolet A (UVA). Due to the timing, a separate visit to the clinic is needed for UV irradiation. The aim of this study was to determine whether a reduction in occlusion time from 24 h to 1 h, in order to simplify the testing procedure, influences test results when photopatch testing with ketoprofen. A total of 22 patients with a known or suspected photo-allergy to ketoprofen were simultaneously photopatch-tested with ketoprofen using both 1 h and 24 h occlusion. One side of the patient's back was irradiated with 5 J/cm2 UVA, and the other side was covered. Measurements were made after 3 days on both irradiated and non-irradiated sides. A total of 20 controls were photopatch-tested with ketoprofen using 1 h occlusion. All of the patients showed positive reactions on the irradiated side. No positive reactions were observed on the non-irradiated side. All controls were negative. In conclusion, 1 h occlusion time is sufficient to establish photo-contact allergy to ketoprofen. No adjustments in UVA or ketoprofen dose were needed. Limiting occlusion time to 1 h could simplify the photopatch test procedure by eliminating one visit to the clinic. These results apply only to ketoprofen; further studies are needed to determine whether a similar approach can be used with other components of photopatch test series.
authors.affiliation: Department of Occupational and Environmental Dermatology, Skåne University Hospital, Malmö, Lund University, SE-205 02 Malmö, Sweden. victoria.marmgren@vgregion.se
authors.forename: Victoria
authors.initials: V
authors.lastname: Marmgren
authors.forename: Monica
authors.initials: M
authors.lastname: Hindsén
authors.forename: Erik
authors.initials: E
authors.lastname: Zimerson
authors.forename: Magnus
authors.initials: M
authors.lastname: Bruze
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000009:adverse effects*; D017454:Dermatitis, Photoallergic / Q000175:diagnosis*; D005260:Female; D006801:Humans; D007660:Ketoprofen / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D010328:Patch Tests / Q000379:methods*; D013997:Time Factors; D014466:Ultraviolet Rays; D055815:Young Adult
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D007660:Ketoprofen