Ho-ho-ho! Gather around, my jolly friends, for I have a tale not of elves and reindeer, but of a quest deep within the human body, where the airways and sinuses embark on a frosty adventure. This story unfolds in a land where chronic rhinosinusitis (CRS) and asthma live side by side, much like the North Pole and its bustling workshop.

In this narrative, our heroes are none other than 108 adult asthmatic patients, each diligently taking their anti-asthmatic medications, including a magical concoction of inhaled corticosteroid and long-acting β2-agonists. These brave souls were divided into two groups: those with CRS, diagnosed by the mystical images of paranasal sinus X-ray and/or osteomeatal-unit CT, and those without, living their lives in the clearer, less congested part of the forest.

Our story takes a curious turn as we discover that the CRS group, much like houses with chimneys needing a good sweep, had higher blood eosinophil counts and levels of FeNO, not to mention a greater prevalence of aspirin-exacerbated respiratory disease (AERD). It seems that, in this tale, not all chimneys are the same, and some require special attention.

But fear not, for our tale has heroes in the form of biomarkers: serum periostin, dipeptidyl peptidase 10 (DPP10), and the mysterious AERD phenotype. These magical markers, through the enchantment of logistic regression and classification/regression tree analyses, have shown themselves to be the guiding stars, leading the way to predict CRS with a sensitivity that would make even the most skeptical elf believe in magic again.

So, as our story comes to a close, remember this, my dear friends: in the real-world clinical setting of our tale, serum periostin, DPP10, and the AERD phenotype shine brightly as valuable biomarkers, guiding those with asthma through the snowy path of predicting chronic rhinosinusitis. And with that, I wish you all a merry journey through the wonders of health and science. Ho-ho-ho!