Common name:	Lettuce
Botanical name:	Lactuca sativa (milk sap)
Family:	Asteraceae (Compositae)
Origin:	Lettuce originates from the wild Lactuca serriola found in the Mediterranean and the Near East (Persia).
Description:	All lettuce cultivars like Cos, Leaf, Butterhead and Iceberg are considered variants of Lactuca sativa. Lettuce has been transformed from an erect plant with bitter leaves to various cultivars, including those with distinctive chlorophyll-deficient leaf heads. The common and Latin name is derived from the milky sap (latex) found in all parts of the {lac, lactis = milk} plane. Latex has a milky sedative effect and lettuce has been grown as an herb. {Note: there is no cross reaction between lettuce latex and natural rubber latex}.

Applications:	A large number of different varieties of lettuce have been raised and are now cultivated worldwide, primarily for use in salads.
Allergens:	Lactucin, lactucopicrin (? Sesquiterpenes)
Allergy:	Lettuce is an occasional cause of allergic contact. dermatitis particularly in food handlers, cooks and market gardeners. It tends to cause dermatitis on the hands, which runs down the forearms. Unfortunately immediate hypersensitivity lettuce has also been reported. This includes Urticaria and life threatening anaphylaxis. The allergy seems to cross-react with chicory and endives, so avoiding these vegetables may also be necessary. It is a form of allergy to compounds, so it can also cross-react with other members of this large family of plants.
Cross reactions:	Chicory and endives
Other information:	Paintings of what appears to be Cos Lettuce have been found in Egyptian tombs dating from 4500 BC. C., although there is some uncertainty about its identity. The first authenticated records of cultivated lettuce date back to Greek historical records in 450 BC. C. In the 1st century AD. C., the Romans cultivated different varieties.
Patch test:	Leaf as is, sesquiterpenic lactone mixture