A comparative study between the two patch test systems Finn chambers and Finn chambers AQUA.

Background: Finn Chambers AQUA (FCA) is a development of the Finn Chambers (FC) test system in which the test chambers are mounted on a moisture‐resistant adhesive patch. FCA has pre‐fixed filter papers. Because the use of FCA does not require any extra taping or use of separate filter papers, a change from FC to FCA chambers may be beneficial for both patients and patch test technicians. Objectives: To investigate whether there are any differences regarding detection of contact allergy when simultaneous patch testing is performed with FC and FCA. Materials and Methods: Results from 434 dermatitis patients simultaneously tested with 10 allergens in both FC and FCA were evaluated. Results: There were no significant differences regarding detection of positive reactions between the two test systems. There were significantly more doubtful reactions to methylisothiazolinone, fragrance mix I and hydroperoxides of linalool when testing with FCA. We only observed significantly more doubtful reactions in FC regarding nickel(II)sulfate. Irritant reactions to formaldehyde were also significantly more common when using FCA. Conclusion: The FC and FCA had good agreement in detection of positive reactions. However, the results including doubtful and irritant reactions justify further research regarding optimization of the dose. [ABSTRACT FROM AUTHOR]