The Mysterious on/Off Itch and Erythema During Whole Body Vibration Exercise

Objectives Intense itch on the legs sometimes associated with redness can be adverse effects of WBV according to the investigators observations and numerous posts in non-professional online-blogs. To the investigators knowledge, the appearance of itch and/or a rash during WBV exercise has not yet been described.

The objectives of this study are:

1. to determine the effect of WBV on itch rating and its unpleasantness and on skin changes.
2. to determine the effect of WBV on serum tryptase.

Hypothesis The working hypothesis is that repeated WBV leads to an increase of itching and erythema. Further investigators hypothesize that repeated WBV does not lead to an increase in serum tryptase.

Inclusion and exclusion criteria will be evaluated. Subjects will be instructed to not shave their legs one week before the intervention day and to shave only the left leg from the ankle to the knee on the day prior to the intervention day.

On the intervention day, subjects will be informed in detail about the study protocol and written informed consent will be collected. If a pregnancy cannot be excluded (days from last menstruation) subjects are instructed to do a pregnancy test. Then, a blood sample will be taken. Subsequently, subjects will be instructed to stand on the vibration plate (Galileo 900) in a slightly crouched position with their hands loosely resting on the rail. Subjects will complete ten 1-minute WBV repetitions interspaced by 1-minute breaks in seated position. During each break, subjects will rate the itch intensity, and skin changes will be captured. Sixty minutes after the last WBV repetition, another blood sample will be taken. Subjects will rest until itch and erythema return to baseline. During resting phase subjects will fill in the Eppendorf itch questionnaire and the Erlanger atopy score.