Practical suggestions to improve standardization of repeated open application testing (ROAT) for daily use products

Repeated open application testing (ROAT) is an important adjuvant in the evaluation of allergic contact dermatitis. There are variations in the way ROAT is used by practitioners and standardizing the method, in terms of the area and amount of the antigen applied, could help improve the validity of the process.

Our study attempts to address ways in which part of the ROAT technique can be standardized - with respect to the area and amount of application and validation of the same through consensus opinion.

Two proposed modifications - one for the area of application (using waterproof surgical markers and a stencil to mark the area of application) and one for daily amount applied (using easily available 1 cm³ syringes), for the ROAT technique were drafted. The same was discussed with a total of 10 dermatologists. The participants were given four statements and were asked to choose one option for each statement (strongly agree - agree - neutral - disagree - strongly disagree). All the respondents were also asked to give their opinion on possible limitations and problems of the proposed modifications and possible solutions for the same.

There was generally a consensus among the 10 dermatologists, with the majority agreeing that the proposed modifications were both effective and practical.

Simple practical modifications of the ROAT technique like marking the area to be applied using a waterproof skin marker and stencil, and the use of 1 cm³ syringes to dispense the test product, can improve the standardization of the process.