Management of asthma in general practice Question patients about occupation and hobbiesBMJ 1994; 308 doi: https://doi.org/10.1136/bmj.308.6922.200 (Published 15 January 1994) Cite this as: BMJ 1994;308:200
EDITOR, - Duncan Keeley correctly addressed the issues concerning treatment of asthma in general practice once the condition has been diagnosed, including the questions to ask during routine consultations to gauge the severity of the disease.1 However, general practitioners need to ask all asthmatic patients one important question before consigning them to lifelong treatment: What are your occupation and leisure interests? Over 200 agents have been proved to cause occupational asthma, ranging from high molecular weight proteins such as bakers' flour, animal fur, fish proteins, and detergent enzymes to low molecular weight isocyanates and glutaraldehyde. Initially patients with occupational asthma do not associate symptoms directly with work, but they wake at night coughing after exposure. Once they have become sensitised they produce specific IgE or IgG antibodies, which cause a more immediate response. During the next long term phase the difference in symptoms at home and work is not obvious. At this stage an absence of symptoms on holidays may be the only clinical clue. Smoking and atopy are variable risk factors depending on the causal agent.
The “single” allergen causing occupational asthma is a fascinating model for natural asthma. Prompt removal from exposure is likely to cure the asthma. Delay in removal and continued antigenic challenge results in cross sensitisation to other household allergens and chronic asthma. The implications for children initially allergic to one type of pet animal are obvious.
Serial peak flow measurements are the best method of diagnosis2 but require careful interpretation. Results can become confused by treatment with β agonists or inhaled steroids.
Herein lies the great opportunity for general practitioners to “cure” a chronic condition that has substantial costs for individual patients and the NHS. New causes and old examples of occupational asthma are always present in general practice.
The final diagnosis of occupational asthma requires specialist help from an occupational physician or chest physician but general practitioners have an important role in the diagnostic chain. They are best equipped to suspect the diagnosis because they know the patient, his or her family, and local industries.