ABSTRACT
Allergy immunotherapy was introduced in 1911 by the reports of Leonard Noon and John Freeman on their injection of increasing doses of timothy pollen extract to patients with a history of hay fever. The use of immunotherapy by injection for treatment of allergic rhinitis and allergic asthma is supported by meta-analyses of randomized, controlled clinical studies. Noon’s original publication reported that immunotherapy induced an increasing resistance of the conjunctiva to instillation of timothy pollen extract. Subcutaneous route (SCIT) causes local reactions at the site of injection and systemic reactions which may be only urticaria or nasal congestion, but can be severe and even fatal bronchospasm or anaphylaxis. Suitable candidates for SCIT with inhalant allergens should have allergic rhinitis or allergic asthma. There are three considerations in preparing an allergen extract for SCIT: using adequate doses, considering cross-reactivity in choosing which extracts to include and avoiding mixing extracts with strong proteolytic activity with extracts containing allergens susceptible to proteolytic activity.
