Subcutaneous administration of allergen vaccines

Subcutaneous allergen immunotherapy (SCIT) was first described in the United States by Noon and Freeman in 1911 (1) and has been used subsequently for the treatment of allergic symptoms due to inhalant allergens. In 1918, Dr. Robert Cooke suggested a mechanism of action for allergen injections as a “desensitization or hyposensitization.” Prausnitz and Kustner elucidated the more specific immunologic basis for allergic disease, demonstrating that allergic sensitivity could be transferred by the serum of a sensitive person to the skin of a nonallergic person (2). SCIT is defined as the repeated administration of specific allergens to patients with IgE-mediated conditions for the purpose of providing protection against the allergic symptoms and inflammatory reactions associated with natural exposure to these allergens (3). The technique of SCIT differs from the process of desensitization, the term applied to the rapid, progressive administration of an allergenic substance, usually a drug, to render effector cells less reactive.