Introduction: The prevelance of allery and asthma has increased rapidly over the last 3 decades and is now estimated that 25-30% of population in Western industrialized countries show symptoms of allergy or asthma. The aim of this study was to reveal the success of allergen immunotherapy (AIT) in Landspitali from 1977-2006.

Material and methods: During the study period a total number of 289 individuals underwent immunotherapy in outpatient clinic of allergy and asthma in Landspítali. A total number of 169 individuals were contacted, of whom 128 (76%) accepted to participate in the study. The evaluation was based on medical records, standardized questionnaire and skin-prick tests.

Results:Patients were evaluated on the average of 20 years after finishing treatment. 118 (92%) patients were desensitized to grass pollen, to birch pollen (30%), cat dander (30%) and dust mite (28%). At the time of the study 67% reported to be asymptomatic or with greatly improved allergy symptoms. Males had better response to AIT than women (p=0.04). Participants with positive family history of allergy and/or asthma in first degree relatives also reported better response to AIT (p=0.02). Furthermore, AIT to grass pollen and dust mite seemed to be more effective than AIT to cat dander and birch (p=0.04). AIT was also shown to reduce asthma.

Conclusion: AIT for 3-5 years provides significant beneficial effect of allergy and asthma symptoms in patients who undergo such  therapy. Finally, it´s findings support the notion that AIT may reduce the risk of new allergic manifestations.

                                                           Male (n=74)                           Female (n=54)

Years since treatment

ended, n(%):

-          less than 2 years:                        1 (1,4%)                                1 (1,9%)

-          2-5 years:                                   4 (5,4%)                                6 (11,1%)

-          6-10 years:                                 3 (4,1%)                                6 (11,1%)

-          11-15 years:                               4 (5,4%)                                5 (9,3%)

-          16-20 years:                              13 (16,2%)                             5 (9,3%)

-          More than 20 years:                  49 (66,2%)                             31 (57,4%)

Average age (years)^a:                          21,1 ± 8,1                               20,7 ± 8,9

Other diseases^b, n(%):                        34 (45,9%)                             22 (40,7%)

Familial history^c, n(%):                      46 (62,2%)                             34 (63,0%)

a: When treatment started.

b: Other than allergy and asthma. Patients status at follow up.

c: Of allergy and asthma in first degree relatives.

Figure 1.:

Figure 2. Age distribution at the treatment initiation. Total of 289 individuals started immune vaccination therapy against allergen during the study period.

Figure 3.:

 

Figure 4. Column chart demonstrating numers of participants vaccinated against known allergen. Participants could be vaccinated against more than one allergen. *Dog and horse dander, fish, parrot and wheat.