Background
Facial allergic contact dermatitis caused by cosmetic products is common. New allergens in cosmetics continuously emerge.

Objectives
To investigate characteristics of patients with facial dermatitis (FD) between 2010 and 2019 including patch test results from cosmetic-related allergens and a new test series with cosmetic-relevant natural ingredients (CRNIs).

Methods
This is a retrospective study analysing demographics, clinical characteristics according to MOAHLFA index (male; occupation; atopic dermatitis; hand; leg; face; age ≥ 40 years), and patch test results to 27 cosmetic-relevant allergens in FD patients. A prospective study evaluating a screening test series with CRNIs in consecutive FD patients for 1 year was also conducted. These patients received a questionnaire for collecting extra characteristics (eg, concerning quality of life).

Results
Of 8740 tested patients, 2292 (26.2%) had FD. Of these, 30.6% had cosmetic-induced FD. The most common cosmetic-related allergens were fragrances and preservatives. The most common patch test-positive CRNIs were hydroperoxides of limonene and linalool, and propolis. Potato and peanut were rare, but the most common prick test-positive CRNIs, however, without any relation to the use of cosmetic products. FD affected nearly all patients' quality of life and caused limitations to their daily life.

Conclusions
Updated management and quick diagnosis of FD is important to avoid negative impact on patients' quality of life.