Diagnosing occupational asthma: the first step is clinical and occupational history which allows to consider the possibility of the disease and its relationship to work. Once occupational asthma is suspected, objective tests such as pulmonary function and skin or blood allergy testing are very useful to confirm the diagnosis. The best available means to give a convincing demonstration that asthma is caused by an occupational agent is the controlled exposure to the agent (specific inhalation challenge) in a laboratory in a specialized centre.

Diagnosing occupational rhinitis: similar to occupational asthma, it is based on clinical and occupational history and on skin or blood allergy testing. In some cases a specific inhalation challenge may be performed, as described above.

Diagnosing occupational dermatitis: it is based on clinical and occupational history, physical examination and skin allergy testing (patch testing).

Diagnosing occupational latex allergy: it is based on clinical and occupational history, skin or blood allergy testing and respiratory function test in the case of respiratory symptoms.