Allergy testing in supermarkets: Misleads susceptible people

BMJ 1994; 308 doi: https://doi.org/10.1136/bmj.308.6927.539 (Published 19 February 1994) Cite this as: BMJ 1994;308:539
  1. A B Kay
  1. Department of Allergy and Clinical Immunology, National Heart and Lung Institute, London SW3 6LY
  2. Safeway, Hayes, Middlesex UB3 4AY.

    EDITOR, - Effective management of patients with allergic disease requires a history and physical examination followed by relevant laboratory tests, including allergy tests, which are chosen primarily on the basis of the patient's history. The tests should be selected and interpreted by the doctor who obtained the history and performed the examination, who should have been trained in, and have experience of, allergic disease. It is regrettable, therefore, that the pharmacy department of the multichain supermarket Safeway is now offering diagnosis of allergy and advice on treatment on the basis of a short questionnaire and a blood test (the Quidel multiallergen dipstick screening test).

    The promotion leaflet states that: “Laboratory analysis can... identify exactly what you are allergic to. There is no need for a doctor's referral. ... We give you sound, sensible advice on how to cope with your allergy.”

    At first sight this may seem a perfectly reasonable commercial venture, with the private sector saving the NHS time and money in diagnosing and managing “mild allergies.” In reality this remote allergy testing may unnecessarily confuse and alarm susceptible people by producing positive results that are not clinically important. Likewise there is a risk of inappropriate advice being given, with overemphasis of the role of allergy in diseases such as asthma and eczema. For example, most asthmatic patients are atopic, but the role of lgE dependent mechanisms in individual patients may be uncertain and can be established only by a professional clinical history.

    Can the pharmacists at Safeway give guidance on the importance of lgE antibodies in chronic asthma? Isn't there a danger that patients might put undue emphasis on the result of allergy tests and reduce or withhold lifesaving treatment such as inhaled or oral corticosteroids? People who suffer from eczema are likely to have IgE antibodies to many aeroallergens and foods, but these are rarely of practical importance, particularly in adults. Many people may go on restrictive diets for their eczema unnecessarily, without adequate supervision.

    A particularly worrying allergy is that to bee and wasp stings since it can be life threatening. A history of severe or even moderate systemic symptoms after a sting, together with a positive IgE antibody level, may indicate immunotherapy. The decision whether to proceed with immunotherapy, however, requires considerable skill and is usually taken by an allergy specialist. Does the supermarket pharmacist have the experience to recognise patients at risk of death from anaphylaxis after further exposure?

    *** We sent the above letter to Safeway for its response. -- ED., BMJ

    Tests performed by qualified pharmacists

    1. J C Ashley,
    2. M J Nelson
    1. Department of Allergy and Clinical Immunology, National Heart and Lung Institute, London SW3 6LY
    2. Safeway, Hayes, Middlesex UB3 4AY.

      EDITOR, - Safeway's pharmacists deal daily with people suffering from asthma, eczema, or allergic rhinitis. It is inconceivable that a pharmacist would compromise a patient's treatment. Already well versed in drug treatment, the pharmacists receive further training before being allowed to offer allergy tests to the public.

      There is little doubt that the incidence of allergy, asthma, eczema, and hay fever is increasing, 1 and in all parts of the globe. The prevalence of IgE antibodies specific to common allergens has also increased, being almost 40% in children.2 The cumulative prevalence of hay fever is 20%, which makes this a common and potentially serious clinical problem. Most asthmatic people (around 85%3) are atopic, and almost three quarters of these are sensitive to house dust as well as other indoor allergens. If animals are kept in the home there are high concentrations of allergen in the air - often 50 times higher than the concentration of house dust mite.4 Removing allergen from the house results in a significant reduction in symptoms, both in children and in adults.5

      A B Kay's letter contains errors. We do not mention diagnosis or offer advice on drug treatment in our literature. We do not advise patients to withhold any drugs they are currently taking. Any findings, especially findings pointing to an allergy to bee or wasp venom, would result in the patients being referred immediately to their general practitioner; this early warning of an allergy to venom might lead to earlier treatment and avert an anaphylactic attack after a bee or wasp sting.

      We believe that our approach at Safeway has the highest ethical, practical, and pharmaceutical standards, and we will do everything we can to work with the medical profession to help this important and large segment of the population.


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