The allergenic compound from tulips linked to the skin condition called tulip fingers is tulipalin A.
Tulipalin A is a naturally occurring compound found in tulips and some related flowers, including alstroemerias. It can cause allergic contact dermatitis after repeated or substantial skin exposure, particularly among florists, bulb growers, and gardeners. The resulting redness, itching, cracking, and swelling of the hands gave rise to the memorable name “tulip fingers.”
The compound is also known as α-methylene-γ-butyrolactone. In an intact plant, much of it is generated when tissue is damaged: tuliposide A is broken down by tuliposide-converting enzymes, releasing tulipalin A. Cutting, handling, or bruising flowers can therefore increase exposure.
Tulipalin A is not the same as urushiol, the allergen associated with poison ivy, nor is tulip fingers a form of sunburn. It is a delayed contact reaction of the immune system, and protective gloves can reduce direct exposure for people who handle tulips professionally.