[Cluster immunotherapy in allergic rhinoconjunctivitis: review of a new therapeutic approach]

Apart from allergen avoidance, specific immunotherapy (SIT) represents the only potentially curative treatment available to patients with allergic rhinoconjunctivitis. Evidence for its clinical efficacy has been clearly demonstrated in several controlled clinical trials and depends on the allergen to which the patient is sensitive, the quality and total amount of allergen administered, and the SIT schedule. In classic SIT, gradually ascending dosages of the allergen extract are injected subcutaneously (dose-increase period) until the individual maximum dose is reached (dose-maintenance period). Several dosage schedules have been worked out. In cluster immunotherapy, 2-3 injections per day of treatment are given once a week to rapidly reach the maintenance dose. Several cluster schedules have been described. Recent data demonstrate that the frequency and severity of adverse effects in cluster immunotherapy correspond to those in other dosage schedules. As far as safety goes, cluster immunotherapy is an interesting alternative for the dose-increase period. In addition, recent studies reveal that clinical benefits appear sooner with cluster immunotherapy.