Qualitative und quantitative Untersuchung des Riechvermögens von Patientinnen und Patienten mit allergischer Rhinitis unter allergenspezifischer Immuntherapie

Being the most widely spread atopic indisposition, with a lifetime prevalance of 14,8% in patients at the age of 18 and 79, allergic rhinitis (AR) represents a significant cost driver for health care systems (Schramm et al., 2003, Nathan, 2007). A global increase of AR prevalence was monitored in the recent years. In addition to common symptoms such as nasal pruritus and sneezing, itching and tearing eyes, AR patients are often suffering from limitations of their ability to smell. The effectiveness of an allergen-specific immunotherapy (AIT) to improve cardinal symptoms and via the consumption of medication, has been demonstrated by numerous scientifc studies. Initial surveys indicate, that AIT also improves AR patients’ ability to smell (Katotomichelakis et al., 2013; Tansuker et al. 2014). As a decreased ability to smell also decreases in many cases the quality of life (Temmel et al., 2002), it seems appropriate to further analyse AIT’s influence on improving the ability to smell. Subsequently, the objective of this pilot study was to determine the connection of the ability to smell of patients with AR and an AIT. The study includes 13 AIT patients and 10 patients in symptomatic therapy with allergen-specific symptoms predominantly apparent in spring (birch pollen) or summer (grass pollen). Both patient groups‘ olfactory capacity was clinically determined by the use of Sniffin’ Sticks before AIT induction in fall//winter, and again during the clinically relevant allergy season (spring/summer) and one year after the AIT induction. Questionaires were used to collect the subjective assessment of the patients’ ability to smell, at the points in time. After one year with AIT, allergic conditions (i.e. rhinitis, eye problems and allergic conditions in general) decreased while the ability to smell and taste, appetite and nose breathing improved in the subjective assessment compared to before commencement of therapy. During the season of the clinically relevant allergy, subjects in symptomatic therapy assessed their discomfort statistically significant stronger and their ability to smell and taste as well as their appetite and nose breathing weaker than patients in AIT. This fact propably indicates that AIT is effective after 6 months of therapy. With regards to identification, discrimination of flavors, olfactory threshold and the total olfactory score, no significant difference of AIT patients compared to the control group became evident. Marginally improved total olfactory score (by 0.75 points) and olfactory threshold (by 0.25 points) became evident after 12 months of therapy. The data does not show statistically significant differences in the ability to smell with respect to age, gender and asthmatic preconditions. Compared to non-smokers, smokers had a statistically significant better ability to smell after 12 months of therapy. This pilot study confirms the results of preceding studies, which have shown that AIT reduces allergic conditions subjectively (Radcliffe, Lampe, & Brostoff, 1996; Mun et al., 2013; Katotomichelakis et al., 2013). Contrasting Katotomichelakis et al. 2013 and Tansuker et al. 2014, this pilot study does only show a marginally improved quantitiatively determined oflactory capacity within the first year of AIT. Compared to symptomatic therapy, AIT provides no statistically significant improvement. The lack of randomization, a small, heterogenous patient population, a short follow-up as well as a non-traceable placebo effect, indicates a potentially limited statistically signifcance of the study’s results. The herewith presented study provides indicators of a correlation of the ability to smell and AIT. Appearing to improve clinical symptoms related to the olfactory organ, it is indicated that AIT does not provide significant benefits over symptomatics therapy with regards to the olfactory capacity.