title: A potent contact allergen of Phacelia (Hydrophyllaceae).
abstract: The major contact allergen of Phacelia crenulata (Hydrophyllaceae) has been identified as geranylhydroquinone. A maximization test of geranylhydroquinone showed this to be a potent sensitizer comparable in degree to poison oak/ivy urushiol. Comparative patch testing on humans with urushiol established that the phacelia allergen does not cross-react with poison oak or ivy.
mesh_terms: D000485:Allergens; D003876:Dermatitis, Atopic / Q000209:etiology*; D003877:Dermatitis, Contact / Q000209:etiology*; D004224:Diterpenes; D006801:Humans; D006873:Hydroquinones / Q000009:adverse effects* / Q000276:immunology; D007114:Immunization; D010328:Patch Tests; D010944:Plants; D013729:Terpenes / Q000009:adverse effects*
chemical_list: D000485:Allergens; D004224:Diterpenes; D006873:Hydroquinones; D013729:Terpenes; C026301:geranylhydroquinone; C026300:geranylgeranylhydroquinone