RESUMO
Immunotherapy units are becoming an increasingly important component of allergy and clinical immunology departments in Spain. The objective of this study was to establish the rate of adverse reactions registered in an immunotherapy unit in Tenerife, Canary Islands, Spain, from May 1998 to May 2000. A total of 5,108 immunotherapy doses were administered to 339 patients (123 males and 216 females): 254 patients (75%) received mite, 48 patients (14.1%) pollen, 7 patients (2%) cat, 2 patients (0.6%) Alternaria alternata, and 38 patients (11.2%) hymenoptera venom immunotherapy; 238 patients (70.2%) had rhinoconjunctivitis and asthma, 59 (17.4%) rhinoconjunctivitis, 5 (1.4%) asthma, and 38 (11.2) hymenoptera sensitivity. A total of 42 episodes of adverse reactions were recorded (0.8% of all the administered doses). Of these reactions, 36 (85.7%) occurred within 30 minutes after the injection was administered, consisting of 15 large local reactions (0.3% of the total amount of injection given) and 21 systemic reactions (0.4%) that occurred only in asthmatic patients. All the systemic reactions were mild and rapidly reversible with appropriate treatment. Only in two cases was an immediate systemic reaction associated with a large local reaction. Six reactions (14.3%) occurred after 30 minutes and consisted only of large local reactions. A total of 15 systemic episodes (71.4% of all the systemic reactions) were registered at initial build-up doses. As to the types of allergens, 14.2% of the individuals receiving cat immunotherapy, 7.8% of the individuals receiving hymenoptera venom, 6.3% of the individuals receiving pollen immunotherapy, and 2.7% of the individuals receiving mite immunotherapy experienced an adverse reaction. Only 0.8% of the administered doses presented any kind of adverse reaction, of which only 0.4% were systemic. The latter were always mild and rapidly reversible with adequate treatment, and there was no vital danger for any patient. Immunotherapy is a safe modality of treatment for allergic respiratory diseases and immunotherapy units provide a controlled and safe environment for its administration.