Four women and one man presented with dermatitis on the eyelids and surrounding areas that began 6 to 36 hours after applying phenylephrine eyedrops. One of these patients had previously had a perinasal eczema elicited by treatment with a preparation containing ephedrine among other drugs. Another patient developed a generalized eczema after taking an anticatarrhal tablet containing pseudoephedrine. In four of the five cases the sensitization to phenylephrine was proved by means of patch tests and intradermal skin tests. In case no. 5, the patch test with phenylephrine was negative and the sensitization was proved by open patch test on the eyelid and intradermal skin test. The patch and intradermal tests with tropicamide were negative in all patients, hence this drug was a good alternative mydriatic in these cases.