Fig. 2

Skin prick test analysis. Wheal and flare reactions (mm) of 17 healthy volunteers with self-reported exposition to disco smoke or shisha and the patient (n = 12) or volunteers without exposition (n = 6) are depicted with a 3 % cinnamon aldehyde in 0.9%NaCl, b 1 % cinnamon aldehyde in Vaseline®, and c 1 % cinnamon alcohol in Vaseline®. Groups were compared using Mann-Whitney U test. * p < 0.05, ** p < 0.01