IGHE and asthma: Medical surveillance programmes should include the following components [178,185,186]: (1) pre-placement and periodic administration of a questionnaire aimed at detecting work-related symptoms; (2) detection of sensitization to occupational agents by means of skin prick tests or serum specific IgE antibodies when these tests are available and standardized; (3) early referral of symptomatic and/or sensitized workers for specialized medical assessment, including NPT in the laboratory and/or at the workplace [52]; and (4) investigation of possible asthma in all workers with confirmed OR.