Allergy: conventional and alternative concepts. Summary of a report of the Royal College of Physicians Committee on Clinical Immunology and Allergy.

Allergy is an exaggerated response of the immune system to external substances. It plays a role in a wide range of diseases. In some, such as summer hayfever, the symptoms are entirely due to allergy. In other conditions, particularly asthma, eczema and urticaria, allergy plays a part in some patients but not all. In these situations, allergy may either have a major role or provide just one of many triggers. In an individual patient's illness, the importance of allergy may change with time. The most common allergens (substances causing allergy) are grass and tree pollens, the house dust mite, products from pets and other animals, agents encountered in industry, wasp and bee venom, drugs, and certain foods. Food allergy presents a particularly difficult problem. Some individuals who react to food suffer from true food allergy but in others there is no evidence of an alteration in the immune system. Here the term 'food intolerance' is preferable. Conventional doctors treat allergy by allergen avoidance--where this is possible--and drugs that relieve symptoms. In a few selected cases, in which other methods have failed, immunotherapy (desensitisation or hyposensitisation) is recommended. Patients who consult practitioners of alternative allergy often do so because they are dissatisfied with the conventional approach to diagnosis and treatment, and sometimes because they have conditions which conventional doctors do not accept as having an allergic basis. There is a very wide range of alternative approaches to allergy, including the methods used by clinical ecologists, acupuncturists and homoeopathists. Hypnosis may have a small role to play in asthma, and similar claims for acupuncture need to be evaluated.(ABSTRACT TRUNCATED AT 250 WORDS)