What is fungal infection of sinus cavity: The inflammation of the paranasal sinuses is defined as Sinusitis. Sinusitis may be due to various reasons like allergy, infection, or autoimmune diseases. When the cause of Sinusitis is infection, it may be bacterial, fungal, or viral. Inflammation or infection of the sinuses by fungi is defined as fungal sinusitis. The fungal infection occurs if the drainage system of nasal cavity is blocked due to any reason and then fungi start growing on the secreted nasal fluid. Aspergillus species are the most common causative agents of fungal sinusitis. [1,2,4]
Signs and symptoms of fungal sinusitis: The various symptoms of fungal sinusitis are running or stuffy nose, headache (first in one side leading to both sides), productive cough, toothaches, bad breaths, and yellowish green thick drips or drainage. It may also lead to fever sometimes. You may also have pain at the infected area of sinus. This pain aggravated on lying down or bending down. [1, 2]
Types of fungal infections in sinus cavity: Fungal infection of sinus can be classified into four types as below:
- Acute invasive sinusitis,
- Allergic fungal sinusitis,
- Chronic invasive sinusitis and
- Fungus ball.
1. Acute invasive sinusitis: Acute invasive sinusitis is a combination of mucormycosis and fulminant invasive fungal sinusitis. It is usually cause by Rhizopus and Mucor. It is mainly observed in immuno compromised patients with diseases like AIDS, diabetes mellitus, and leukemia. It is usually diagnosed with biopsy and treated with several antifungal drugs. 
2. Allergic fungal sinusitis: Allergic fungal sinusitis is defined as an allergic reaction to aerosolized environmental dematiaceous fungi in immuno competent patients. It targets usually to patients with history of allergic rhinitis. The mucin and fungal debris develop in the sinus cavities. The only treatment is the surgical removal of allergens. 
3. Chronic invasive sinusitis: Chronic invasive sinusitis is a progressive disease. It is further explained as granulomatous infections for long time. It extends beyond the sinus walls of sinus cavities. It many target immuno competent patients similar to allergic fungal infection. It also hits atopic hosts. The main causative organism is Aspergillus. Its infection invades quite similarly to local aggressive neoplasm. The adjuvant therapy for chronic invasive sinusitis is Amphotericin B. However Ketoconazole may be used as replacement therapy when fungal cultures and sensitivities are available. 
4. Fungus Ball: Fungus ball is a clump of fungus exists in respiratory track. It is also known as mycetoma and aspergilloma. Aspergillus organism is generally involved in this type of infections. The fungal ball infection of sinus occurs mostly in maxillary sinus region. Aspergillus targets to the patients with history of recurrent sinus. The most common symptom of Fungus ball is that the infected person coughs with bleeding. This may sometimes converts in life threatening conditions. Surgery is done mostly to remove the Aspergilloma. Itraconazole is the only drug available in the market to treat this condition; however it is reported that Itraconazole results are not very effective treatment for fungus ball. 
The recent studies reported that fungal infections are causing most cases of chronic rhino sinusitis. Most fungal sinus infections are benign or noninvasive in nature, except when they infect in patients who are immune compromised. 
Treatments of fungal infections of sinus cavities: Fungal infections can be treated by various ways like antibiotics, corticosteroids and surgeries. The antibiotics like Amoxicillin, Augmentin, Clarithromycin, and Doxycycline are used to treat sinusitis however these are not so effective in most of the patients. Corticosteroids are used as post surgery as long-term treatment for reducing recurrences of fungal infections. The most prominent and widely used method of treatment is surgery.