[Skin testing with cosmetics brought in by patients].

Detailed analysis of symptoms indicates which skin tests should be performed in a patient presenting an allergic reaction to cosmetics: the tests should be read after 15 to 60 min for immediate reactions and after 48 and either 72 or 96 h for eczematous reactions. If the results are inconclusive, additional tests should be performed (ROAT, re-test, usage test). Discrepancies between clinical symptoms and tests results should raise a suspicion of false-positive or false-negative tests.