The Effect of Odors on Asthma Symptoms

Universitaire Ziekenhuizen KU Leuven

Status: Invitation-only

Conditions: Asthma

Treatments: Behavioral: Therapeutic Suggestion; Behavioral: Asthmogenic Suggestion; Other: Phenylethyl Alcohol odor

Study type: Interventional

Funder types: Other

Identifiers

NCT02624362

S57940

Details and patient eligibility

About

An extended replication of Jaen & Dalton (2014), the investigators aim to investigate the role of odors and associated trigger beliefs on symptom perception and airway inflammation in individuals with asthma

Full description

Participants with asthma are randomly assigned to a 15-min (phenylethyl alcohol) odor inhalation, accompanied by either an asthmogenic suggestion (nocebo), or a therapeutic suggestion (placebo). Airway inflammation, lung function, and asthma symptoms are measured in response to the odor/suggestion, up to 24 hours after odor inhalation. The investigators are also measuring worry and heart rate variability as potential mediators of the response.

Enrollment: 48 estimated patients

Sex: All

Ages: 18 to 65 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• A physician diagnosis of asthma

Exclusion criteria

• FEV1 lower than 60% predicted
• clinical condition other than asthma

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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48 participants in 2 patient groups

Odor+ Positive belief

Experimental group

Description:

Participants receive 15 minute odor presentation (Phenylethyl Alcohol odor) accompanied by the suggestion that this odor improves asthma symptoms (therapeutic suggestion)

Treatment:

Other: Phenylethyl Alcohol odor

Behavioral: Therapeutic Suggestion

Odor + Negative belief

Experimental group

Description:

Participants receive 15 minute odor presentation (Phenylethyl Alcohol odor) accompanied by the suggestion that this odor worsens asthma symptoms (asthmogenic suggestion)

Treatment:

Other: Phenylethyl Alcohol odor

Behavioral: Asthmogenic Suggestion