Open-Label Placebos Improve Symptoms in Allergic Rhinitis: A Randomized Controlled Trial

It is well known that placebo treatment may have a significant impact on allergic symptoms [1,2,3]. In the traditional view, deception of the patient is crucial for beneficial responses due to placebo treatment [4]. However, a recent study demonstrated intriguing evidence that placebos may work even without concealment in patients with irritable bowel syndrome [5]. This is important because ethical problems related to placebos (e.g. undermining trust in the patient-physician relationship) do not account when using open-label placebos. Here we report a pilot study investigating whether placebos without deception may also work for allergic rhinitis.We conducted a two-group randomized controlled trial including 25 participants with allergic rhinitis. Patients were randomized into two groups. One group received placebos without deception (open-label placebo group), and the other group received no pills (control group). Patient-provider relationship and amount of contact time was held similar for both groups. After 2 weeks we tested whether symptoms and quality of life may have changed due to the open-label placebos. Participants were recruited from fliers in the local university and via social media (mean age 26 ± 9.9 years, 21 women). The study was done in accordance with the Declaration of Helsinki and approved by an ethical board. All participants provided written informed consent. Allergic rhinitis had to be diagnosed by a physician. Only participants taking medication were included. Participants were asked not to change medications or dosages during the study. Before assigning each of the participants randomly to the groups, all subjects were briefed in the same way [5]: we explained that placebos are inactive substances and that they contain no medications. Participants were further told that although placebos contain no medication, placebo effects may still be powerful. The effect was explained to them by pointing out that the body may automatically respond to taking placebo pills, like Pavlov's dogs that salivated when they heard the bell. In addition, they were told that a positive attitude may be helpful for the placebo effect, but is not necessary. Last, they were told that those participants who were in the placebo group needed to take the placebos faithfully. After this briefing the participants were asked to assess their allergic symptoms by using a questionnaire describing different symptoms (itching, prickling, or burning feelings in the nose; constipated or running nose; impaired sense of smell or taste; sneezing fits; feeling like having a cold; itching or irritated skin; eczema on the skin; itching, burning or red eyes; billowed eyelids; itching, prickling or scratching feelings in the throat; sore throat; burning feeling or mucus in the mouth or throat; billowed mucosa; breathlessness; cough; headaches; feelings of exhaustion; lack of concentration; tiredness, and disorders of the gastrointestinal tract). Participants were asked to indicate their response on a 7-point scale ranging from ‘never' (1) to ‘always' (7). For further analysis we calculated a composite score including all symptoms. Furthermore, we asked the subjects to indicate their subjective wellbeing (SF-12 [6]). Then, the participants were randomized to one of the two groups. Participants in the placebo group received a white tube containing 28 placebo pills. The tube was labeled with the logo of the local university and the following information: ‘placebo pills (28), take one in the morning and one before night for 14 days'. Participants in the control group received no pills at all. Symptoms of the groups before starting the trial were not different [t(23) = 1.58, p > 0.1]. After 2 weeks, all participants were invited for a second examination to assess again their allergic symptoms (both groups were investigated on the same dates). When comparing the development of symptoms between the groups we found a significant interaction between group and time (ANOVA with factors group and time, F1, 23 = 3.96, p = 0.05). Post hoc t tests revealed that the allergic symptoms of the open-label placebo group significantly decreased over time [t(10) = 2.83, p = 0.01, two-sided; pretest: 3.55 ± 0.73, posttest: 2.67 ± 1.05, change: 0.88], whereas the control group demonstrated only a slight improvement, which was not significant [t(13) = 1.41, p > 0.1, pretest: 3.11 ± 0.66, posttest: 2.88 ± 0.77, change: 0.23] (fig. 1). With regard to single symptoms we found no responses to the treatment for headaches, tiredness, disorders of the gastrointestinal tract, breathlessness, billowed eyelids, itching, prickling, or burning feelings in the nose, impaired sense of smell or taste, and mucus in the throat (all p > 0.1). There were no significant effects for the outcome measure quality of life (ANOVA with factors group and time). However, the improvement of symptoms for the open-label placebo group was significantly related to the subjective wellbeing (SF-12, r = 0.74, p = 0.009, Pearson, two-sided). The analog correlation for the control group failed to reach the level of significance (r = 0.34, p > 0.1).Our results suggest that open-label placebos seem to improve symptoms of allergic rhinitis better than a control group with comparable patient-adviser contact. The effects of open-label placebos are in line with previous results on different diseases, e.g. irritable bowel syndrome [5,7,8,9]. These results may support the use of placebo effects beyond their use as controls in clinical trials [10]. However, several limitations of our study should be noted. First of all, the sample size of this pilot study is very small. Thus, the results need to be replicated with a larger sample. Second, the trial reported here was mainly experimental, and a therapeutic application of these principles will have to involve more patients. Third, our trail duration was rather short, and we do not know whether there are long-term effects. A longer follow-up study is needed in order to draw clear conclusions for clinical implications. Last, our data includes only subjective data. Future studies should also involve more objective data (e.g. biological data), which are not prone to effects such as social desirability.To our knowledge, this is the first randomized controlled study suggesting that open-label placebos may have an effect on allergic rhinitis. Although this outcome should be supported by further research, we believe that the results are encouraging. The authors declare that they have no relevant conflicts of interest.