Garlic is a well recognised cause of allergic contact dermatitis and urticaria. Patch testing using neat garlic can cause false-positive reactions because of diallyl disulfide found in the bulb acting as an irritant on the skin.
Diallyl disulfide is used as a garlic flavouring in food and garlic oil.
There is no information on syndromes associated with garlic allergy.
Garlic is in the Alliaceae plant family, other plants in this family are chives, leeks and onions. If your allergy is severe these plants may also cause allergic reactions.