title: Allergic and photoallergic contact dermatitis: a 10-year experience.
abstract: BACKGROUND
  Photoallergic contact dermatitis (PACD) is a hypersensitivity reaction that occurs when a previously photosensitized exogenous agent comes into contact with UV radiation. Currently, there are no studies profiling photoallergic reactions in Canada. Because the photoallergen profile changes over time, it is necessary to continually update our knowledge to ensure proper recognition of allergens and appropriate treatment of patients.
  
  
  OBJECTIVE
  This study aimed to profile photoallergic reactions in Canada.
  
  
  METHODS
  A retrospective chart review of all patients who underwent photopatch testing at Toronto Western Hospital between January 2001 and December 2010 was completed. Photoallergic, allergic, and irritant reactions were recorded for 26 common allergens.
  
  
  RESULTS
  Ninety-nine patients (61.9%) had at least 1 positive reaction to the test allergens. Fifty-four patients (33.8%) had at least 1 photoallergic reaction. All 26 allergens produced at least 1 allergic or photoallergic reaction. The most common relevant photoallergens were benzophenone-3, octyl dimethyl para-aminobenzoic acid (PABA) in 5% alcohol, and butylmethoxy-dibenzoylmethane.
  
  
  CONCLUSIONS
  This study is the first to profile photoallergic contact reactions in Canada. It is clear that the culprit photoallergen in PACD can often be identified in a properly selected population. Future surveillance is necessary to continue to characterize PACD trends in Canada and to help better treat and screen this patient population.
authors: Schulich School of Medicine and Dentistry, London, Ontario, Canada. jillgreenspoon@gmail.com
authors: Jill
authors: J
authors: Greenspoon
authors: Renita
authors: R
authors: Ahluwalia
authors: Naznin
authors: N
authors: Juma
authors: Cheryl F
authors: CF
authors: Rosen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000485:Allergens / Q000009:adverse effects*; D002170:Canada / Q000453:epidemiology; D017449:Dermatitis, Allergic Contact / Q000453:epidemiology / Q000209:etiology*; D017454:Dermatitis, Photoallergic / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010328:Patch Tests / Q000379:methods; D017319:Photosensitizing Agents / Q000009:adverse effects; D012189:Retrospective Studies; D013473:Sunscreening Agents / Q000009:adverse effects*; D014466:Ultraviolet Rays / Q000009:adverse effects; D055815:Young Adult
chemical_list: D000485:Allergens; D017319:Photosensitizing Agents; D013473:Sunscreening Agents