08/01/2026
Allergic rhinitis is nasal inflammation from allergens (sneezing, clear runny nose, itchy eyes/nose), while acute sinusitis involves infected sinus cavities, causing facial pain/pressure, thick colored mucus (yellow/green), headache, and sometimes fever, often developing from a cold. The key differences are: rhinitis has itching and clear discharge (allergies), while sinusitis brings pain, pressure, and thick, discolored mucus (infection/inflammation), often lasting longer.