The main difference between allergies and sinus infection is that allergies are an inflammatory response to allergens (like pollen), and sinus infections result when there is a build up of bacteria or fungi in the sinus passages. Though chronic allergies may result in secondary sinus infections, these two conditions are wholly separate and respond to different treatments. On the other hand, sometimes treating allergies may prevent sinus infections from occurring. Sinusitis may occur in other instances, such as after colds or other viruses, so this won’t always work. Each condition additionally has some unique symptoms that may make it easier to tell the two apart.
The principal symptoms of nasal allergies are clear or white mucus that runs from the nose, itchy nose, and watery eyes. Most people tend to recover from these symptoms if they get away from the offending allergen. If the allergen, like a cat or houseplants, remains nearby, people can develop chronic allergies. They may feel like they always have serious congestion.
What shouldn’t be felt is sensation of pain or pressure around the eyes, cheeks and forehead. Also unusual would be any kind of fever. Nasal discharge should be white or milky, and discharge that is green, grey or dark yellow, and gets bloody is not standard. These symptoms indicate sinus infection: pressure, pain, thicker colored mucus, and possibly fever. Both conditions can last a long time, but sinus infections last far longer than transient allergies.
Understanding the differences between allergies and sinus infection leads to questions about how each are treated. For brief allergies, no treatment may be necessary. Alternately, some people with seasonal allergies take an occasional antihistamine, as needed, if they have considerable pollen exposure. Chronic allergies are generally better treated on a daily basis with medicines that can help reduce inflammatory response. These could include nasal spray or oral medications.
Treating chronic allergies may be advised because some people have allergies and sinus infection concurrently, or they’re prone to infection when allergic response isn’t under control. As mucus is allowed to sit or get stuck in the sinuses it can become a breeding ground for germs like strep or for certain fungi. Some sinus infections are avoided by reducing inflammation so that the ability to breed germs in the sinuses is reduced.
When a sinus infection is not avoided, it will require treatment. Most people have common bacterial infections and take antibiotics for a few weeks. Some people get fungal infections instead. These are harder to identify, but once diagnosed, they require antifungal medication. Another of the differences between allergies and sinus infection is that any type of antihistamine may have little to no effect on sinusitis, and certainly won’t cure the illness. In the reverse, antibiotics or antifungal medicines don’t tame chronic allergies.
