Related Experiment Videos
Repeated open application tests (ROAT) in patients allergic to colophony--evaluated visually and with bioengineering
1Department of Occupational and Environmental Dermatology, Karolinska Hospital, Stockholm, Sweden.
Acta Dermato-Venereologica
|April 16, 1998
Summary
The repeated open application test (ROAT) can help confirm clinical relevance after a positive patch test for colophony allergy. Results showed ROAT identified colophony sensitivity in most allergic subjects, correlating with patch test findings.
Area of Science:
- Dermatology
- Allergology
- Contact Dermatitis Research
Background:
- Patch testing is a standard method for diagnosing allergic contact dermatitis.
- The clinical relevance of a positive patch test often requires further investigation.
- The repeated open application test (ROAT) is a proposed supplementary method for assessing clinical relevance.
Purpose of the Study:
- To compare the diagnostic outcomes of patch testing with the results of repeated open application tests (ROATs) for colophony allergy.
- To evaluate the correlation between patch test sensitivity and ROAT outcomes.
- To assess the utility of objective bioengineering techniques versus visual assessment in ROAT evaluations.
Main Methods:
- 13 colophony-sensitive subjects and 9 controls underwent serial dilution patch testing with colophony.
- Subjects then performed ROATs using three concentrations of colophony solution applied daily for 2 weeks.
- Test sites were assessed visually and using bioengineering techniques before each application.
Main Results:
- 10 out of 13 colophony-sensitive subjects reacted in ROATs to a 20% colophony solution; 4 also reacted to 1%.
- No control subjects showed reactions in the ROATs.
- A correlation was observed between the threshold concentration identified in patch testing and the ROAT outcomes.
- Significant variation in reactivity was noted among subjects during ROATs.
- Objective bioengineering measures provided no additional information beyond visual assessment for ROAT evaluation.
Conclusions:
- ROAT is a valuable supplementary method for confirming the clinical relevance of positive patch tests in colophony allergy.
- ROAT results correlate with patch test findings, aiding in the assessment of allergic contact dermatitis.
- Visual assessment appears sufficient for evaluating ROAT reactions, without a clear benefit from objective bioengineering techniques in this study.