Sesquiterpene lactone allergy.

Sesquiterpene lactones are a large, diverse group of chemicals found in several plant families that cause allergic contact dermatitis. The biological, botanical, allergenic, and structural significance of sesquiterpene lactones is explored as well as the clinical characteristics of cutaneous reactions. The association with UV-light sensitivity and proposed mechanisms for this relationship as well as new developments in patch test methods and treatment are reviewed.