The Urticaria Study and Research Group (Groupe d'Etudes et de Researches de l'Urticaria, G.E.R.U.) was formed in the Dermatology Department of the Hôpital Michel Levy in 1983 and now it continues to operate in the new Dermatology Department of the C.H.U. Timone Adultes. This has been possible because in four years 400 cases of urticaria have been seen and computerized information on these will appear in the next issue. As a result of this experience, we have been able to lay out a prospective study and develop a rigorous methodology.