Pirker C, Möslinger T, Koller D Y, Götz M, Jarisch R
Dermatologic and Pediatric Allergy Clinic, Vienna, Austria.
Contact Dermatitis. 1992 Apr;26(4):217-9. doi: 10.1111/j.1600-0536.1992.tb00231.x.
A 69-year-old patient, with known mercury and adhesive plaster allergy, developed facial dermatitis within 24 h of contact with arnica (Arnica). Skin testing showed positive reactions to arnica and, among various other plants of the Compositae, also to Tagetes sp. hybr. (marigold). Cross-reactivity between Tagetes and arnica has not previously been described.