Parsley
Parsley is one of the more common herbs regularly used in cooking and as a garnish. It can be a hidden problem for some individuals. For example:
Kauppinen et al identified 12 people who reacted to parsley with urticaria and angioedema. [2]
A 26 year old man experienced oral allergy syndrome whenever he ate parsley. [3]
A young woman experienced acute rhino conjunctivitis, facial swelling, itching in the mouth and ears, and red itchy palms and soles within five minutes of eating potatoes with a sauce containing parsley and sweet oil. Testing showed that parsley was the culprit. [4]
Although particular conditions have been mentioned above it is important to remember that any food can cause any condition. See the food intolerance articles or read Change Your Diet and Change Your Life.
REFERENCES
(1) Cordobés-Durán C, García-Menaya JM, Lombardero M, Ledesma A, Bobadilla P. Detection of a 12-kilodalton lipid transfer protein allergen in parsley. J Investig Allergol Clin Immunol. 2007;17(4):282-3.
(2) Kauppinen K, Kousa M, Reunala T. Aromatic plants--a cause of severe attacks of angio-edema and urticaria. Contact Dermatitis. 1980 Jun;6(4):251-4.
(3) Raap U, Schaefer T, Kapp A, Wedi B. Exotic food allergy: anaphylactic reaction to lychee. J Investig Allergol Clin Immunol. 2007;17(3):199-201.