Over 99% of homes contain at least one allergen, with 75% harboring three to six, yet winter allergies often masquerade as stubborn “colds” or recurrent respiratory infections. This episode confronts the core diagnostic challenge of differentiating allergy-driven symptoms from viral, bacterial, or non-allergic triggers in colder months. We delve into indoor allergen epidemiology, risk stratification for polysensitized patients, syndrome overlap in differential diagnosis, and utility of location-specific respiratory allergen profiles for diagnostic testing and interpretation. Additional topics include guideline-informed approaches to environmental exposure reduction, patient-centered therapeutic strategies, monitoring of symptom thresholds, actionable counseling for managing dust mites, pet dander, molds, mouse and cockroach allergens, and streamlining through tailored lab ordering guides and reflex pet component testing. Clinicians will gain practical insight into identifying sensitizations, guiding targeted exposure minimization, and elevating respiratory care quality for patients with persistent winter symptoms.

Link to resources and references: https://www.thermofisher.com/phadia/us/en/resources/immunocast/indoor-allergens-winter-respiratory-symptoms-clinician-guide.html?cid=0ct_3pc_05032024_9SGOV4