How good is the Australian baseline series at detecting allergic contact dermatitis?

Patch testing is the gold standard for the diagnosis of allergic contact dermatitis (ACD). The Australian Baseline Series (ABS) was formulated by our group to include the 60 most common and relevant allergens in our patient population. The aim of this study was to assess the efficacy of testing with the Australian Baseline Series in order to diagnose allergic contact dermatitis.

We conducted a retrospective study of 964 patients with ACD diagnosed at our centre from 1 January 2012 to 31 December 2018. Patients with at least one relevant positive reaction were stratified into three groups: i) reactions only to allergens in the Australian Baseline Series; ii) reactions to allergens in the Australian Baseline Series and to additional allergens; and iii) reactions only to allergens not present in the Australian Baseline Series.

The Australian Baseline Series alone was successful in identifying the cause of allergic contact dermatitis in 63.4% (611/964) of patients. In 23.0% (222/964), the Australian Baseline Series detected at least one relevant allergen, but there were relevant allergens outside of the Australian Baseline Series as well. In 13.6% (141/964), no relevant allergens were detected in the Australian Baseline Series, but allergens were detected in additional series or by testing patients' own products. The most frequently occurring allergens not included in the Australian Baseline Series were citral, ammonium persulfate, geraniol, oakmoss absolute and chlorhexidine diacetate.

The Australian Baseline Series is an adequate screening tool for identifying patients with ACD. Nevertheless, females should be additionally routinely tested with the fragrance series. Patients with suspected occupationally related dermatitis should always be tested with additional allergens and own products.