Additives and preservatives in commercial foods have been implicated in the etiology of chronic urticaria, but such foods have not been widely accepted. In some countries, as in ours, people prefer to use home-made foodstuffs to avoid potentially hazardous commercial additives. However, not all home-made foodstuffs are safe, especially regarding allergies. In this report, we describe a patient with chronic urticaria due to home-made canned tomato prepared using "tomato drug" as a "safe (!)" additive.