Sinusitis

Below, I have listed are some of the causes that may lead to acute sinusitis or chronic sinusitis. 

Allergies

Sinusitis caused by allergies happen when a substance your body identifies as an allergen causes the nasal passages to swell. The items that cause an allergic reaction differs for every person, but common items include: pollen, mold, dust mites, pet hair. 

Allergies typically cause acute sinusitis. The symptoms only present themselves as you come into contact with the allergens. However, environmental factors could contribute to chronic sinusitis. For instance, if the patient is frequently in contact with the source of allergens, such as household pets, or mold in the living area. Usually, nasal sprays work well to alleviate symptoms of allergic sinusitis.

Bacterial Infection

Bacterial Infection happens when bacteria infects the lining of your nasal cavities and passages, thus causing sinusitis. Generally I would look for any of the following symptoms as signs of a bacterial infection as well: 

1. If infection persists longer than 10 days without alleviation of symptoms or observable clinical improvement;
2. Fever above 38.9˚C;
3. Postnasal Drip is present;
4. Symptoms progressively get worse after 5-6 days, instead of getting better.

Fungal Infection

Sinusitis caused by fungal infection is less common than the above types of sinusitis. Unless there are other conditions that compromise the immune system, such as diabetes, leukemia, lymphoma or immunodeficiencies, our bodies are typically able to ward off fungal infections quite easily. Medications that suppress the immune system may encourage fungal infections too.

Symptoms of fungal sinusitis are largely similar to other forms of sinusitis. However, in an individual with a compromised immune system, the sinusitis symptoms experienced can be more severe, such as pain or numbness in the facial regions, swelling of cheeks and/or eyelids, or even colour changes in the skin.