Contact sensitivity to lichens and compositae in Frullania dermatitis

48 patients with allergic contact dermatitis from Frullania were patch tested with a lichen mix, compositae and lichen acids. 27 were sensitive to Frullania and lichens. Parmelia caperata and Parmelia reticulata were positive in all, and in a descending order of positivity: Pseudovernia furfuracea, Evernia prunastri, Usnea spp, Ramalina lusitanica. d-Usnic and evernic acids and atranorin were the main responsible allergens.