Definition: Fungal Sinusitis describes different conditions when fungi are involved in the causes or symptoms of sinus or nasal inflammations.
Classification (Types):
Noninvasive: (extra mucosal)
I. Fungal ball.
II. Allergic fungal sinusitis.
Invasive: (submucosal invasion)
III. Fulminant type [acute form]
IV. Indolent type [chronic form]
I. Fungal ball
It occurs in hyperimmune (atopic) individuals. Maxillary sinus is the most common followed by sphenoid sinus. Mainly caused by aspergillus.
Symptoms: Nasal discharge and posterior nasal drip.
Signs: Nasal discharge from the affected sinus seen endoscopically.
Investigations:
C.T.: Unilateral opacity affecting maxillary and/or sphenoid sinus with metallic dense shadow at center.
Treatment:
Surgical: Transnasal endoscopic surgery: Middle meatal antrostomy and/or sphenoidotomy with removal of the fungal ball and profuse irrigation.
Recurrence: uncommon.
II. Allergic fungal sinusitis
Usually occurs in immune competent individuals. Origin is mostly from the ethmoids and maxillary sinuses.
Etiology: caused by allergy to fungi mainly Aspergillus and Alternaria.
Symptoms:
- Nasal obstruction: Usually unilateral, of gradual onset and progressive course.
- Anterior nasal discharge: usually unilateral, thick, tenacious and offensive.
- Proptosis: unilateral and only in advanced cases especially in children.
Signs:
- Unilateral, multiple, soft, gray and glistening nasal polyps, arising mainly from the middle meatus.
- Unilateral thick, yellow and mucoid nasal discharge and/or fungal mud.
Investigations:
- Endoscopy: polyps, mud and mucin mainly at the middle meatus.
- CT: usually unilateral opacity affecting the nose and/or one or more paranasal sinuses associated with characteristic calcifications and mottling in soft tissue window images.
- Biopsy: polyps with eosinophils and fungus hyphae.
Treatment:
a. Medical:
- Nasal Saline wash
- Corticosteroids: systemic and local
- Immunotherapy.
b. Surgical:
Transnasal endoscopic pan sinus surgery aiming at
- Removal of all the polyps, mucin and fungal debris.
- Offering proper aeration and drainage of the affected sinuses
Recurrence: common.
III. Invasive fulminant type
Occurs in immune compromised individual e.g. diabetes, uremia, AIDS, patients under cytotoxic or steroid therapy.
Organism: Mucormycosis causing intravascular thrombosis and gangrene.
Progress: acute onset, rapidly progressive course, and lethal in short time in uncontrolled cases.
Symptoms:
- Early: Pain, headache and fever.
- Late: unilateral nasal obstruction, ocular and/or cranial symptoms.
Signs:
- Black intranasal structures including inferior and/or middle turbinate, later on the nasal septum, gangrenous skin of the cheek, and gangrene and perforation of the palate.
- Offensive nasal discharge
- Ocular extension may lead to proptosis, ophthalmoplegia and blindness.
- Cranial extension may lead to cranial nerve palsies, coma and lastly death.
Investigations:
1. CT:
- Early: unilateral opacity of the turbinate/s and/or ethmoid sinus.
- Late: unilateral extensive opacity involving most of the sinuses and extending beyond the sinonasal framework to the orbit and/or cranial cavity.
2. Biopsy: necrotic gangrenous tissue and intramucosal fungal hyphae.
Treatment:
- Surgical debridement of all the gangrenous tissue.
- Systemic antifungal drugs (Amphotericin B). The patient should be hospitalized and the liver and kidney functions monitored daily.
- Control of the original disease causing the immune compromised status.
Prognosis: very bad.
IV. Indolent fungal sinusitis
Occurs in immune competent individuals.
Organism: Aspergillus.
Progress: insidious onset slowly progressive course, lethal after long time.
Symptoms:
- Unilateral obstruction, discharge, ocular and/or cranial symptoms in advanced cases.
Signs:
- Unilateral reddish nasal mass. Ocular and cranial affection occur late
Investigations:
1. CT: unilateral extensive opacity involving most of the sinuses and extending beyond the sinonasal framework to the orbit and cranial cavity in late cases.
2. Biopsy: Granuloma and fungal hyphae.
Treatment:
Surgical debridement, with antifungal drugs: systemic intravenous voriconazole.
Prognosis: bad.
Key points
- Fungal rhinosinusitis should be considered in all resistant cases of chronic rhinosinusitis.
- Mucosal Invasion is the main stay in classification.
- Immunity should be considered whether immunocompetent, immune compromised or hyper immune (atopic).
- Management differs dramatically according to type of infection.
