Sinusitis caused by allergens

Sinusitis caused by allergens occurs when the sinuses become inflamed due to reactions to substances like pollen, dust mites, or pet dander. When these allergens enter the nasal passages, they can trigger an immune response, leading to swelling and mucus buildup in the sinuses. This can result in symptoms such as nasal congestion, facial pain, and a runny nose. Unlike infections, which are caused by bacteria or viruses, allergen-induced sinusitis often improves when the allergens are removed or treated with medications like antihistamines or nasal corticosteroids.