Related Experiment Videos
Contact dermatitis with negative patch tests: the additive effect of allergens in combination
1University Department of Dermatology, Royal Victoria Infirmary, Newcastle upon Tyne, U.K.
The British Journal of Dermatology
|May 1, 1990
Summary
Conventional single allergen patch testing is insufficient for diagnosing contact dermatitis. Combining allergens can lower individual detection thresholds, revealing sensitivities missed by standard tests.
Area of Science:
- Dermatology
- Allergology
- Immunology
Background:
- Contact dermatitis diagnosis relies on patch testing.
- Sensitivity to multiple allergens can complicate diagnosis.
- Conventional testing may miss synergistic effects of allergens.
Purpose of the Study:
- To evaluate the adequacy of conventional patch testing for multiple allergen sensitivity.
- To investigate the dose-response relationship of single versus combined allergens.
- To determine if allergen combinations affect individual sensitivity thresholds.
Main Methods:
- Studied 14 patients with known dual allergen sensitivity.
- Tested allergen pairs (10 combinations from 15 common allergens) singly and combined.
- Used serial dilutions in chloroform and paraffin, measuring skin-fold thickness.
- Related response to log-dose of allergens.
Main Results:
- Single allergens below detection threshold elicited a response when combined.
- The presence of one allergen lowered the detection threshold for another.
- Combined allergen responses were additive on the linear dose-response curve.
- Responses approached but did not exceed the sum of individual responses near the plateau.
Conclusions:
- Conventional single allergen patch testing is inadequate for diagnosing contact dermatitis.
- Allergen interactions influence patch test sensitivity.
- Combined allergen testing may be necessary for comprehensive diagnosis.