Abstract
Contact dermatitis from frullania mainly affects people living in the country. The 2 most frequent species in Europe, Frullania dilatata and Frullania tamarisci, do not cross‐react: both species must be patch tested when frullania intolerance is suspected. Yet patch testing with Frullania may be hazardous 9 out of 37 cases recorded in Strasbourg correspond to active sensitization by the tests. Since routine testing is risky, only aimed testing can be recommended.