Pattern of patch test reactivity among patients with clinical diagnosis of contact dermatitis: a hospital-based study.
OBJECTIVE
Contact allergy is associated with a significant morbidity all over the world. This study was performed to investigate the pattern of sensitization by contact allergens in the local population.


METHODS
Retrospective study to investigate patch test reactivity among patients with clinical diagnosis of contact dermatitis who were referred to the allergy clinic at the King Khalid University Hospital, Riyadh, between April 2008 and March 2010.


METHODS
Of the 196 patients referred to the allergy clinic over the 2-year period, 91 (46.4%) patients reacted to one or more patch test allergens, and these patients were included in this study. The study group included 82 (91.1%) of Saudi nationality and 9 (8.9%) patients of other nationalities. The patch test was performed using the T.R.U.E TEST, containing 24 allergens/allergen mixes.


RESULTS
Of the 91 cases who reacted positively to one or more allergens, 67 (73.6%) were females with a mean age of 37 (8.3 years) and 24 (26.4%) were males with a mean age of 34 (11.6 years). Thirty-three (36.2%) patients reacted to nickel sulfate, 14 (15.3%) to p-phenylenediamine, 13 (14.2%) to p-tert-butylphenol-formaldehyde resin, 13 (14.2%) to thimerosal, and 9 (9.8%) to colophony. Reactivity against the rest of the allergens was not remarkable. A significantly higher percentage of females reacted to nickel sulfate (84.8% vs 15.2% in males;P=.0001), p-tert-butylphenol-formaldehyde resin (92.3% vs 7.7%; P=.0001), and thimerosal (76.9% vs 23.1%;P=.03).


CONCLUSIONS
Patch test reactivity to nickel sulfate was high. The pattern of contact allergy observed in this study indicates the need for large-scale investigations to identify local allergens responsible for contact allergy and for formulation of policies directed towards avoidance of exposure.
Department of Pathology, College of Medicine and University Hospitals, King Saud University, Riyadh, Saudi Arabia.
Adel
A
Almogren
Zahid
Z
Shakoor
Mohammad Osman
MO
GadEl Rab
Mustafa Hussein
MH
Adam
D000328:Adult; D000485:Allergens / Q000276:immunology*; D017449:Dermatitis, Allergic Contact / Q000175:diagnosis* / Q000209:etiology / Q000276:immunology; D005260:Female; D006785:Hospitals, University; D006801:Humans; D008297:Male; D008875:Middle Aged; D009532:Nickel / Q000276:immunology; D010328:Patch Tests / Q000379:methods*; D012189:Retrospective Studies; D012529:Saudi Arabia; D055815:Young Adult
D000485:Allergens; C029938:nickel sulfate; D009532:Nickel