RESUMEN
BACKGROUND: The allergic asthma is the reversible chronic inflammatory process at the airways, secondary to exaggerate reply to the allergens exposition, its treatment includes: avoiding the exposure to allergens, pharmacology therapy and the specific immunotherapy with allergens (ITA), which is based on the growing dosages of the extract allergenic; the objectives are to modify the immune response and to improve the allergic disease. The ITA can fail due to causes attributable to the patient, vaccine-inherent causes and/or factors related to the allergic disease. OBJECTIVE: To determine the main causes of specific immunotherapy with allergens' failure in our hospital. MATERIAL AND METHODS: In the present study 126 records of patients with allergic asthma treated in the extern consultation service of the clinical immunology and allergy department of the CMN 20 de Noviembre, ISSSTE, were reviewed from January 1996 to December 2001. RESULTS: It was found that specific immunotherapy with allergens, failed in 32 (23%) patients. Main causes of failure were: 1) withdrawal in the vaccine application in 19 (59%) patients; 2) high serum levels of IgE. The co-morbidities that contribute to poor responses to the treatment were: obesity, gastroesofageal reflux and chronic rhynosinusitis. CONCLUSIONS: Specific immunotherapy with allergens is an alternative method of allergic asthma's treatment which has been approved by national and international medical consensus. Main causes of failure in our hospital are the abandon of treatment and high serum levels of IgE, as well as the existence of other conditions.