[Occupational allergies: magnitude of the problem].

The prevalence of allergic diseases is progressively increasing, but the proportion attributable to occupational agents is not completely known. Most epidemiological data regards occupational asthma due to sensitising agents, which is the most common and frequently compensated occupational respiratory disease. The epidemiology of the so called "irritant asthma" and of occupational rhinitis is less clear, although rhinitis is often associated to asthma and/or precedes its clinical manifestation. The epidemiology of occupational allergic dermatitis has not been completely investigated as well. The present paper is introductory on some selected papers presented in the First Regional Conference on Occupational Allergic Diseases which has been held in Pavia in 1999 with the main goal of giving a picture of the situation of these diseases in our country.