Tips for diagnosing occupational illness & ruling out non-occupational causes

Any illness resulting from a variety of biological, chemical, physical, and psychological factors that are present in the work environment can be defined as an occupational disease (OD). ILO has revised the list of ODs in 2010.    Scientific evidence of the causes and patterns of ODs form the knowledge base in the diagnosis of individual cases. When establishing a causal relationship with a specific agent, exposure or work process and disease, assessment of exposure, entry routes, dose-response, and consistency of symptoms and reactions with the level and duration of exposure should be considered. Individual susceptibility and habits can modify the form and onset of OD. Physiological state such as pregnancy is extending the effects of work exposures to the next generation.     Some ODs are common, such as musculo-skeletal strain injuries, but largely ignored. ODs with a long lag time between exposure and outcome can be difficult to detect. Varying symptoms that can be mixed to non-occupational causes are challenging in differential diagnosis. Diagnostic procedures and interpretation of test results is not always easy. Multiple exposures pose an extra diagnostic challenge as well as new agents potential of causing ODs. Constant vigilance must be kept to start investigations if clustering of work-related cases is detected.    Delays in diagnosis of ODs include gaps in OSH knowledge, lack of surveillance, inaccessibility to health care, delayed investigations or referral, and fear of job loss. Poor record keeping and reporting of ODs is prevalent and leads to an unrealistic picture of the magnitude of the problem in many countries.     Diagnosis of OD is not an end of the process, but a start for the primary prevention. Always inform employer and workers of the OD risks, initiate practical changes at work to minimize exposure, and refer a patient to vocational rehabilitation when needed.