Immunotherapy has been enthusiastically adopted as the treatment of choice for allergic rhinitis and asthma in North America and Europe. In the UK and South Africa, the procedure has never become as popular but is used as a treatment option in grass pollen allergic rhinitis and for bee or wasp sting anaphylaxis. This report cautioned against the use of immunotherapy in general practice and cited 26 anaphylactic deaths over 30 years. These deaths arose mainly as a result of inappropriate and injudicious use of the procedure in treating uncontrolled asthma. Critics would therefore say that immunotherapy is a potentially life-threatening treatment for rather harmless, although inconvenient diseases.
Immunotherapy does however definitely have a place in selected patient groups.
The exact immuno-modulatory mechanism by which immunotherapy switches off allergies is uncertain. Researchers then postulated that specific IgG4 antibodies where induced towards the offending allergen. An associated reduction in mucosal mast cell numbers and a decrease in antigen-induced eosinophil migration to the site of inflammation is noted during immunotherapy. Another equally important consideration is whether the patient is likely to be compliant and adhere to this regular treatment regime for 3-5 years. The ideal candidate is a severely allergic person who is unable to avoid the offending allergen in daily life and in who drug therapy has failed to control the allergy or in whom drug side-effects have become intolerable.