What causes an itchy nose, runny nose, and sneezing?

Itchy nose, runny nose, and sneezing may be caused by various factors, mainly including: 1. Allergic rhinitis: The most common cause. When exposed to allergens (such as pollen, dust mites, pet dander, etc.), the nasal passages may have an allergic reaction leading to these symptoms. 2. Common cold or flu: Viral or bacterial infections can also cause these symptoms, often accompanied by other cold symptoms such as dry throat and sore throat. 3. Environmental irritants: Air pollution, changes in temperature and humidity, or irritation from foreign substances may stimulate the nasal passages and cause the above symptoms. 4. Nasal polyps: Polyps in the nasal cavity may cause nasal congestion, itchy nose, and runny nose. If symptoms persist or worsen, timely medical consultation is recommended to identify the exact cause and receive appropriate treatment.