Repeated open application tests

A patient with a contact allergic reaction to a topical antimycotic drug formulation that contained benzoyl alcohol had positive patch tests on day 4 and a positive repeated open application test to benzoyl alcohol 5% in petroleum jelly (3). 

Patch tests in patients with anogenital eczema should include the standard series cinchocaine HCl, propolis, bufexamac, and other ingredients of topical formulations according to the patient s history. In cases of doubt, the repeated open application test (ROAT) is recommended. Patients should be advised to apply the suspected product three times a day for 3 days to an area of healthy skin on measuring 5 cm x 5 cm the flexural site of the forearm (35). 

Johansen JD, Bruze M, Andersen KE, Frosch PJ, Dreier B, White IR, Rastogi S, Lepoittevin JP, Menne T. The repeated open application test suggestions for a scale of evaluation. Contact Dermatitis 1998 39(2) 95-6. 

Hannuksela M, Salo H. The repeated open application test (ROAT). Contact Dermatitis 1986 14(4) 221-227. 

Flyvholm M-A, Hall BM, Agner T, et al. 1997. Threshold for occluded formaldehyde patch test in formaldehyde-sensitive patients Relationship to repeated open application test with a product containing formaldehyde releaser. Contact Dermatitis 36 26-33. 

IgE Immunoglobulin E ROAT Repeated open application test... 

Patch testing and/or photopatch testing, which are performed in the usual way. There are no specific techniques that are recommended for airborne dermatitis. The methodology also includes additional procedures, such as open tests, repeated open-application tests and, eventually, use tests. 

Hannuksela A, Niinim i A, Hannuksela M (1993) Size of the test area does not affect the result of the repeated open application test. Contact Dermatitis 28 299-300 Hjorfti N, Roed-Petersen J (1976) Occupational protein contact dermatitis in food handlers. Contact Dermatitis 2 28-42 Johansson J, Lahti A (1988) Topical non-steroidal anti-inflammatory drugs inhibit non-immunologic immediate contact reactions. Contact Dermatitis 19 161-165 Kujala T, Lahti A (1989) Duration of inhibition of non-immunologic immediate contact reactions by acetylsalicylic acid. Contact Dermatitis 21 60-61... 

Perform additional testing procedures with the suspected allergen(s), products brought by the patient presumably containing the suspected dlergen and product s extracts Perform patch test with serial dilution Perform provocative use test Perform repeated open-application test... 

Details of the performance of the repeated open-application test (ROAT) and its relevance are given in textbooks (Rietschel and Fowler 1995 Wahiberg 1995). 

The concentration of the allergen in the product may be too low to cause a positive response. Moreover, the allergen may not be liberated in sufficient quantity, or the occlusion may be insufficient, so that other testing methods might be required. In certain cases, repeated open-application tests (ROAT) (Hannuksela and Salo 1986) can be useful. With the semi-open test method (Dooms-Goossens 1995), it is possible to use undiluted chemicals, but the penetration may be too low to induce test reactions. If a product is under serious suspicion, the different ingredients should be tested individually. 

Clinical relevance of a positive patch-test reaction may exist for at least 55-65% of positive results. Strongly positive patch test reactions (2+ or 3+) are more likely to be associated with a positive fragrance history than a weak or doubtful reaction (Frosch et al. 1995b). A positive ROAT (repeated open application test, twice daily application on the antecubital fossa for a maximum of two weeks) (Johansen et al. 1996) with fragrance ingredients makes relevance of the reaction more likely. 

Information regarding test concentrations and vehicles are rarely available - for the examining dermatologist, the testing is a question of trial and error. If a positive reaction is obtained, it is crucial to carry out serial dilution tests and to test a sufficient number of controls (>25). So far, provocative use tests, such as the repeated open application test (ROAT), do not seem to have been used to clarify the relevance of a positive patch-test reaction to a solvent. 

Such tests are suitable for identifying highly irritant material, not for comparing irritancy potential of different products. Repeated open application tests are also frequently used to verify the clinical significance of allergic patch test reactions [55]. 

Hannuksela and Hannuksela [152] compared the development of irritant reactions in a wash test in a repeated open application test (ROAT) and in a chamber test by using a hand dishwashing liquid. They showed that the results of the chamber test and of the ROAT do not accurately predict the results of the wash test. 

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