A 53-year-old farm worker presented with a 3-year history of an occupational allergic contact dermatitis to asparagus. The dermatitis cleared quickly with courses of systemic corticosteroids but relapsed within days of further exposure to asparagus. The genera Asparagus is made up of some 300 species. It belongs to the family Liliaceae which includes tulips, onions and garlic. Asparagus contains asparagin, coniferin and the glucoside vanillin. The allergen may be a plant growth inhibitor, 1,2,3-Trithiane-5-carboxylic acid, which is present in young shoots.