Abstract:  We report the case of an adolescent boy with aquagenic urticaria unresponsive to oral antihistamine therapy. We successfully treated his condition by topical application of a petrolatum-containing cream as a protective coating. To our knowledge, this is the first report showing the use of topical therapy alone to treat aquagenic urticaria in a child. Based on the effectiveness, safety profile, and ease of use, clinicians may wish to consider this regimen as a first-line therapy.