The additive value of patch testing with patients' own products at an occupational dermatology clinic.
OBJECTIVE
Patch testing with commercially available kits detects only 70-80% of relevant allergens in patients with contact dermatitis. This is not ideal, especially when occupational issues are being evaluated. This study analyses our data regarding reactions to patients' own products.


METHODS
In a 5-year period, 1532 patients were assessed in our occupational dermatology clinic.


RESULTS
We found that 101 patients (6.6%) reacted to their own samples. In 20 (1.3%) cases, reacting to their own samples was the only clue for detecting the responsible allergen. In 59 (3.9%) cases, testing with their own samples reinforced their reactions to commercial allergens.


CONCLUSIONS
We found the overall additive value of testing with patients' own products to be 5.2%. This is not a low proportion considering the 20-30% false negative rate when patch testing. Patch testing with patients' own samples, appropriately diluted should be undertaken whenever possible.
Slodownik
Dan
D
Occupational Dermatology Research and Education Centre, Skin and Cancer Foundation Inc., Carlton South, Victoria, Australia.
Williams
Jason
J
Frowen
Kathryn
K
Palmer
Amanda
A
Matheson
Melanie
M
Nixon
Rosemary
R
D000328:Adult; D000368:Aged; D000485:Allergens / Q000276:immunology; D001315:Australia; D016009:Chi-Square Distribution; D009783:Dermatitis, Occupational / Q000175:diagnosis* / Q000276:immunology; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure / Q000009:adverse effects; D009790:Occupations; D010328:Patch Tests / Q000379:methods*
D000485:Allergens