A retrospective study of 2585 patients patch tested with the European standard series in Hong Kong (1995-99).
BACKGROUND
Data on patch test findings in Hong Kong are scarce, with the last survey performed more than 10 years ago. A retrospective analysis of results from all patch tests performed on patients with suspected allergic contact dermatitis from January 1995 to December 1999 in the Social Hygiene Service, which provides a public dermatology service in Hong Kong, was undertaken. We aimed to explore the demographic data associated with positive reactions and the profile of contact sensitizing allergens in Hong Kong.


METHODS
A total of 2585 patients were patch tested with the European standard series during the period. Most were Chinese, with a female-to-male ratio of 3 : 2.


RESULTS
One or more positive responses were noted in 1415 patients (54.7%). The most common allergen was nickel sulfate (24.4%), followed by fragrance mix (13.7%), cobalt chloride (8.7%), p-phenylenediamine (6.0%), and balsam of Peru (5.7%). Nickel sensitivity was more common in female patients, and dichromate sensitivity was more common in male patients (P < 0.001). Female gender, an age of 40 years or below, truncal and upper limb involvement, absence of lower limb involvement, and a positive atopy history were significant risk factors for nickel sensitivity.


CONCLUSIONS
This study provides a profile of allergens responsible for allergic contact dermatitis in the public dermatology service in Hong Kong. A prospective study, using a larger panel of allergens, involving patients from both the private and public sectors, would provide a more comprehensive profile of contact allergens in Hong Kong and contribute to the establishment of a local standard series.
Lam
Wai Sun
WS
Social Hygiene Service, Department of Health, and Department of Community and Family Medicine, Chinese University of Hong Kong, Hong Kong, China. drwslam@yahoo.com.hk
Chan
Loi Yuen
LY
Ho
Stanley Ching Kong
SC
Chong
Lai Yin
LY
So
Win Han
WH
Wong
Tze Wai
TW
D000328:Adult; D017677:Age Distribution; D000485:Allergens / Q000009:adverse effects; D016587:Antimutagenic Agents / Q000009:adverse effects; D001453:Balsams / Q000009:adverse effects; D003035:Cobalt / Q000009:adverse effects; D017449:Dermatitis, Allergic Contact / Q000175:diagnosis* / Q000453:epidemiology; D005260:Female; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D007509:Irritants / Q000009:adverse effects; D008297:Male; D009532:Nickel / Q000009:adverse effects; D010328:Patch Tests; D010476:Perfume / Q000009:adverse effects; D010655:Phenylenediamines / Q000009:adverse effects; D012189:Retrospective Studies; D017678:Sex Distribution
D000485:Allergens; D016587:Antimutagenic Agents; D001453:Balsams; D007509:Irritants; D010476:Perfume; D010655:Phenylenediamines; D003035:Cobalt; C029938:nickel sulfate; D009532:Nickel; C025080:Peruvian balsam; C018021:cobaltous chloride