title: Retrospective study of photopatch testing in a Chinese population during a 7-year period.
abstract: BACKGROUND
  Photoallergic contact dermatitis (PACD) is of importance in a proportion of photodermatoses and can be evaluated through photopatch testing (PPT).
  
  
  OBJECTIVE
  The objectives of this study were to evaluate the results of PPT and investigate the prevalence of PACD reactions to different photoallergens in Chinese patients at the Department of Dermatology of Huashan Hospital Fudan University during a 7-year period.
  
  
  METHODS
  A retrospective PPT study was conducted. During the 7 years, 4957 patients attending for investigation of suspected photodermatoses were tested according to the European consensus methodology with up to 14 allergens prepared according to Chinese National Standards. The reactions were scored using the International Contact Dermatitis Research Group visual scoring system.
  
  
  RESULTS
  A total of 3472 PACD reactions in 2454 subjects (49.5%) were recorded. The most common agents were chlorpromazine (44.3%), followed by para-aminobenzoic acid (14.7%), thimerosal (8.9%), and sulfanilamide (6.9%). Allergic contact dermatitis reactions comprised 409 reactions in 399 subjects (8%). Photoinhibition and photoaugmentation of allergic contact dermatitis compromised 3810 reactions in 2412 subjects and 11 reactions in 11 subjects, respectively. Irritant reactions (1928 reactions) were seen in 1140 subjects.
  
  
  CONCLUSIONS
  The most predominant photoallergens in our region were chlorpromazine, para-aminobenzoic acid, thimerosal, and sulfanilamide, which likely reflected the particular exposures of this Chinese population.
authors.affiliation: From the Department of Dermatology, Huashan Hospital Fudan University, Shanghai, People's Republic of China.
authors.forename: Lujuan
authors.initials: L
authors.lastname: Gao
authors.forename: Yue
authors.initials: Y
authors.lastname: Hu
authors.forename: Chunya
authors.initials: C
authors.lastname: Ni
authors.forename: Yu
authors.initials: Y
authors.lastname: Xu
authors.forename: Li
authors.initials: L
authors.lastname: Ma
authors.forename: Shuxian
authors.initials: S
authors.lastname: Yan
authors.forename: Xia
authors.initials: X
authors.lastname: Dou
mesh_terms: D010129:4-Aminobenzoic Acid / Q000009:adverse effects; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000485:Allergens / Q000009:adverse effects*; D002648:Child; D002681:China; D002746:Chlorpromazine / Q000009:adverse effects; D017449:Dermatitis, Allergic Contact / Q000209:etiology; D017454:Dermatitis, Photoallergic / Q000209:etiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010328:Patch Tests; D012189:Retrospective Studies; D000077145:Sulfanilamide; D013424:Sulfanilamides / Q000009:adverse effects; D013849:Thimerosal / Q000009:adverse effects; D014466:Ultraviolet Rays / Q000009:adverse effects; D055815:Young Adult
chemical_list: D000485:Allergens; D013424:Sulfanilamides; D000077145:Sulfanilamide; D013849:Thimerosal; D010129:4-Aminobenzoic Acid; D002746:Chlorpromazine