Allergen immunotherapy (desensitisation) for allergic diseases.

tion) involves the repeated administration of allergen extracts to allergic individuals to induce a state of clinical and immunological tolerance. Traditionally, this has involved repeated subcutaneous injections of incremental doses of allergen over a period of 8–16 weeks followed by monthly ‘maintenance’ injections for 3–5 years. Modified approaches have included shorter and preseasonal regimens and alternative routes of administration, particularly the sublingual route. Immunotherapy is indicated in patients with immunoglobulin (Ig) E-dependent disease and is particularly effective in patients with insect venom anaphylaxis and in those with severe seasonal allergic rhinitis unresponsive to anti-allergic drugs. The risk/benefit should be assessed in every case. In view of the remote risk of systemic side effects, immunotherapy should be prescribed and given only by trained and experienced individuals with access to resuscitative measures.1