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Fungal Infection Of Nose And Paranasal Sinuses | Additional Nasal Conditions | Nose | Otorhinolaryngology (Ear Nose Throat / E.N.T) | 4th Year (Fourth Year) | MBBS | Detailed Free Notes

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1. EXAM-READY DEFINITION

  • Fungal infection of the nose and paranasal sinuses, also called fungal rhinosinusitis, is a spectrum of diseases caused by colonization or invasion of fungal organisms involving the nasal cavity and paranasal sinuses.

  • It ranges from non-invasive, benign conditions to rapidly progressive, life-threatening invasive infections, particularly in immunocompromised patients.

One-Line University Answer

Fungal rhinosinusitis is infection of the nasal cavity and paranasal sinuses caused by fungi, which may be non-invasive or invasive.

2. WHY THIS TOPIC IS EXTREMELY IMPORTANT

  • Frequently asked in:

    • Long questions

    • Short notes

    • Viva (especially mucormycosis)

  • High mortality if missed

  • COVID-era relevance (post-COVID mucormycosis)

  • Tests clinical judgment + radiology + pathology

3. CLASSIFICATION OF FUNGAL RHINOSINUSITIS (VERY HIGH-YIELD)

3.1 MAJOR CLASSIFICATION (EXAM FAVORITE)

A. NON-INVASIVE FUNGAL RHINOSINUSITIS

  • Allergic fungal rhinosinusitis (AFRS)

  • Fungal ball (Mycetoma)

B. INVASIVE FUNGAL RHINOSINUSITIS

  • Acute invasive (Fulminant) fungal rhinosinusitis

  • Chronic invasive fungal rhinosinusitis

  • Chronic granulomatous fungal rhinosinusitis

Exam Line

Fungal rhinosinusitis is classified into non-invasive and invasive forms.

4. EPIDEMIOLOGY (EXAM-RELEVANT)

4.1 GEOGRAPHICAL DISTRIBUTION

  • Common in:

    • Tropical and subtropical regions

    • Developing countries

  • Increasing incidence worldwide

4.2 PREDISPOSING POPULATION

  • Immunocompetent:

    • AFRS

    • Fungal ball

  • Immunocompromised:

    • Diabetes mellitus

    • Diabetic ketoacidosis

    • Hematological malignancies

    • Steroid therapy

    • Post-COVID patients

4.3 AGE GROUP

  • AFRS: Young adults

  • Invasive fungal sinusitis: Middle-aged to elderly

5. APPLIED ANATOMY (CORE ENT EXAM SECTION)

5.1 COMMONLY INVOLVED SINUSES

  • Maxillary sinus (most common)

  • Ethmoid sinus

  • Sphenoid sinus

  • Frontal sinus (less common)

5.2 ANATOMICAL FACTORS FAVORING FUNGAL GROWTH

  • Poor sinus ventilation

  • Ostial obstruction

  • Stagnant secretions

  • Warm, moist environment

5.3 IMPORTANT NEIGHBORING STRUCTURES (EXAM ALERT)

  • Orbit (via lamina papyracea)

  • Skull base

  • Cavernous sinus

  • Internal carotid artery (sphenoid sinus)

6. ETIOLOGY (STEP-WISE, HIGH-YIELD)

6.1 COMMON FUNGAL ORGANISMS

NON-INVASIVE

  • Aspergillus fumigatus

  • Aspergillus flavus

INVASIVE

  • Mucor

  • Rhizopus

  • Aspergillus species

Exam Line

Mucormycosis is most commonly caused by Rhizopus species.

6.2 PREDISPOSING FACTORS

  • Diabetes mellitus (most important)

  • Ketoacidosis

  • Immunosuppression

  • Prolonged steroid use

  • Iron overload

  • Poor nasal hygiene

7. PATHOGENESIS (VERY HIGH-YIELD)

7.1 NON-INVASIVE FUNGAL RHINOSINUSITIS

  • Fungi colonize sinus cavity

  • No tissue invasion

  • Host immune response causes symptoms

7.2 ALLERGIC FUNGAL RHINOSINUSITIS (AFRS)

  • Type I hypersensitivity reaction

  • IgE-mediated immune response

  • Thick allergic mucin

  • Fungal elements present but do not invade tissue

7.3 INVASIVE FUNGAL RHINOSINUSITIS

  • Fungal hyphae invade blood vessels

  • Causes:

    • Thrombosis

    • Ischemia

    • Tissue necrosis

  • Rapid spread to:

    • Orbit

    • Brain

Exam Line

Angioinvasion is the hallmark of invasive fungal sinusitis.

8. MORPHOLOGY / PATHOLOGY

8.1 GROSS FEATURES

AFRS

  • Thick, brownish-green allergic mucin

  • Nasal polyps

  • Sinus expansion

FUNGAL BALL

  • Cheesy, clay-like mass

  • Confined to sinus

  • No mucosal invasion

INVASIVE FUNGAL SINUSITIS

  • Black necrotic tissue

  • Eschar formation

  • Pale ischemic mucosa

8.2 MICROSCOPIC FEATURES

ALLERGIC FUNGAL RHINOSINUSITIS

  • Eosinophils

  • Charcot–Leyden crystals

  • Non-invasive fungal hyphae

MUCORMYCOSIS

  • Broad, ribbon-like hyphae

  • Non-septate

  • Right-angle branching

ASPERGILLOSIS

  • Narrow, septate hyphae

  • Acute-angle branching

Exam Line

Broad non-septate hyphae with right-angle branching are characteristic of mucormycosis.

9. CLINICAL FEATURES — GENERAL (CORE EXAM CONTENT)

9.1 NASAL SYMPTOMS

  • Nasal obstruction

  • Nasal discharge

  • Foul smell

  • Crusting

9.2 FACIAL SYMPTOMS

  • Facial pain

  • Facial swelling

  • Headache

9.3 ORBITAL SYMPTOMS (RED FLAG)

  • Periorbital edema

  • Proptosis

  • Diplopia

  • Loss of vision

9.4 SYSTEMIC FEATURES

  • Fever

  • Malaise

  • Poor glycemic control (diabetics)

10. CLINICAL FEATURES BY TYPE (INTRODUCTORY)

10.1 ALLERGIC FUNGAL RHINOSINUSITIS

  • Young patient

  • Nasal polyps

  • Thick allergic mucin

  • Asthma association

10.2 FUNGAL BALL

  • Usually unilateral

  • Minimal symptoms

  • Incidentally detected on CT

10.3 INVASIVE FUNGAL SINUSITIS

  • Rapid progression

  • Severe pain

  • Black eschar

  • Cranial nerve involvement

11. DIAGNOSIS — INTRODUCTION

  • Requires:

    • High clinical suspicion

    • Nasal endoscopy

    • CT/MRI

    • Histopathology

(Detailed investigations, management, complications, OSCE, MCQs in PART 2 & PART 3)

Written And Compiled By Sir Hunain Zia (AYLOTI), World Record Holder With 154 Total A Grades, 7 Distinctions And 11 World Records For Educate A Change MBBS 4th Year (Fourth Year / Professional) Otorhinolaryngology (ENT) Free Material

12. DIAGNOSTIC APPROACH (STEP-BY-STEP, EXAM-ORIENTED)

12.1 CLINICAL SUSPICION (FIRST & MOST IMPORTANT STEP)

  • Any patient with:

    • Uncontrolled diabetes

    • Post-COVID steroid use

    • Rapidly progressive sinus symptoms

    • Orbital pain, diplopia, vision loss

    • Black nasal crusts or eschar

  • Must be considered invasive fungal rhinosinusitis until proven otherwise

Exam Line

A high index of suspicion is crucial for early diagnosis of invasive fungal sinusitis.

12.2 NASAL ENDOSCOPY (ENT CORNERSTONE)

  • Findings in Non-Invasive Disease

    • Thick allergic mucin (AFRS)

    • Nasal polyps

    • Clay-like debris (fungal ball)

  • Findings in Invasive Disease

    • Pale ischemic mucosa

    • Black necrotic tissue (eschar)

    • Bleeding on touch may be absent due to thrombosis

Pearl

Absence of bleeding on probing suggests vascular invasion.

13. IMAGING — RADIOLOGY CORRELATION (VERY HIGH-YIELD)

13.1 CT SCAN (PNS) — FIRST-LINE IMAGING

  • Advantages

    • Defines bony anatomy

    • Detects sinus opacification

    • Surgical planning

CT FINDINGS BY TYPE

  • AFRS

    • Hyperdense sinus contents

    • Sinus expansion

    • Bone remodeling (pressure erosion)

  • Fungal Ball

    • Hyperattenuating focus

    • Usually unilateral maxillary sinus

  • Invasive Fungal Sinusitis

    • Bony erosion

    • Extrasinus extension

    • Orbital involvement

Exam Line

Hyperdense sinus contents on CT suggest fungal sinusitis.

13.2 MRI — WHEN & WHY

  • Indications

    • Orbital symptoms

    • Intracranial extension

    • Vascular invasion suspicion

  • MRI Findings

    • Low signal on T2 (fungal elements)

    • Cavernous sinus involvement

    • Internal carotid artery encasement

Exam Line

MRI is superior to CT for detecting soft-tissue and intracranial involvement.

14. LABORATORY INVESTIGATIONS

14.1 BLOOD TESTS

  • CBC: Leukocytosis

  • ESR / CRP: Raised

  • Blood glucose levels

  • Renal function tests (baseline before antifungals)

14.2 MICROBIOLOGICAL STUDIES

  • KOH mount:

    • Rapid, bedside test

    • Demonstrates fungal hyphae

  • Fungal culture:

    • Species identification

    • Takes time

14.3 HISTOPATHOLOGY (GOLD STANDARD)

  • Confirms:

    • Tissue invasion

    • Angioinvasion

  • Differentiates invasive vs non-invasive disease

Exam Line

Histopathology demonstrating angioinvasion confirms invasive fungal sinusitis.

Written And Compiled By Sir Hunain Zia (AYLOTI), World Record Holder With 154 Total A Grades, 7 Distinctions And 11 World Records For Educate A Change MBBS 4th Year (Fourth Year / Professional) Otorhinolaryngology (ENT) Free Material

15. DIFFERENTIAL DIAGNOSIS (TABLE — EXAM FAVORITE)

Condition Key Feature Differentiation
Bacterial sinusitis Purulent discharge No hyperdensity, no necrosis
Nasal polyposis Bilateral polyps No fungal debris
Granulomatosis with polyangiitis Systemic vasculitis c-ANCA positive
Sinonasal malignancy Epistaxis, mass Biopsy confirms
Tuberculous sinusitis Chronic, indolent Caseating granulomas

16. PRINCIPLES OF MANAGEMENT (CORE EXAM SECTION)

16.1 GENERAL PRINCIPLES

  • Early diagnosis

  • Rapid initiation of therapy

  • Multidisciplinary approach:

    • ENT

    • Medicine

    • Ophthalmology

    • Neurosurgery

  • Correction of predisposing factors

17. MEDICAL MANAGEMENT (TYPE-WISE, DETAILED)

17.1 NON-INVASIVE FUNGAL RHINOSINUSITIS

A. ALLERGIC FUNGAL RHINOSINUSITIS

  • Oral corticosteroids

  • Topical nasal steroids

  • Antihistamines

  • Saline nasal irrigation

  • Surgery for clearance (see below)

B. FUNGAL BALL

  • Surgery is primary treatment

  • Antifungals not routinely required

17.2 INVASIVE FUNGAL RHINOSINUSITIS (EMERGENCY)

A. SYSTEMIC ANTIFUNGAL THERAPY

  • First-line

    • Amphotericin B (liposomal preferred)

  • Alternatives

    • Posaconazole

    • Isavuconazole

Important Points

  • Start immediately on suspicion

  • Adjust dose based on renal function

  • Prolonged therapy required

Exam Line

Liposomal amphotericin B is the drug of choice for invasive fungal sinusitis.

B. CONTROL OF PREDISPOSING FACTORS

  • Strict glycemic control

  • Stop or reduce steroids

  • Correct acidosis

  • Treat immunosuppression

18. SURGICAL MANAGEMENT (VERY HIGH-YIELD)

18.1 INDICATIONS

  • All invasive fungal sinusitis

  • AFRS with obstruction

  • Fungal ball

18.2 PROCEDURES

  • Functional Endoscopic Sinus Surgery (FESS)

    • Removal of fungal debris

    • Wide sinus drainage

  • Debridement

    • Remove all necrotic tissue

    • Repeat debridement often required

  • Orbital decompression

    • If vision threatened

  • Maxillectomy / craniofacial resection

    • Rare, extensive disease

Exam Line

Surgery aims to remove necrotic tissue and reduce fungal load.

Written And Compiled By Sir Hunain Zia (AYLOTI), World Record Holder With 154 Total A Grades, 7 Distinctions And 11 World Records For Educate A Change MBBS 4th Year (Fourth Year / Professional) Otorhinolaryngology (ENT) Free Material

19. POST-OPERATIVE CARE & FOLLOW-UP

  • Long-term antifungal therapy

  • Serial nasal endoscopy

  • Imaging follow-up

  • Monitor renal & hepatic function

  • Glycemic control

20. COMPLICATIONS OF FUNGAL RHINOSINUSITIS (VERY HIGH-YIELD)

Complications depend on whether the disease is non-invasive or invasive, with invasive forms being rapidly progressive and life-threatening.

20.1 LOCAL COMPLICATIONS

  • Persistent nasal obstruction

  • Septal perforation

  • Turbinate necrosis

  • Palatal ulceration and perforation

  • Facial cellulitis

  • Facial abscess

Pathological Basis

  • Angioinvasion → thrombosis → ischemia → tissue necrosis

20.2 ORBITAL COMPLICATIONS (EXAM FAVORITE)

  • Preseptal cellulitis

  • Orbital cellulitis

  • Subperiosteal abscess

  • Orbital abscess

  • Optic neuritis

  • Permanent vision loss

Clinical Red Flags

  • Sudden visual deterioration

  • Ophthalmoplegia

  • Proptosis

  • Relative afferent pupillary defect

20.3 INTRACRANIAL COMPLICATIONS (MOST DANGEROUS)

  • Cavernous sinus thrombosis

  • Meningitis

  • Brain abscess

  • Subdural empyema

  • Epidural abscess

Exam Line

Intracranial complications are more common with sphenoid and frontal sinus involvement.

20.4 VASCULAR COMPLICATIONS

  • Internal carotid artery thrombosis

  • Stroke

  • Hemorrhagic infarction

21. PROGNOSIS (EXAM-RELEVANT)

21.1 NON-INVASIVE DISEASE

  • Excellent prognosis

  • High recurrence in AFRS if long-term follow-up neglected

21.2 INVASIVE FUNGAL RHINOSINUSITIS

  • Mortality rate: 30–80%

  • Prognosis depends on:

    • Early diagnosis

    • Glycemic control

    • Rapid surgical debridement

    • Timely antifungal therapy

Poor Prognostic Factors

  • Delayed presentation

  • Cranial nerve involvement

  • Intracranial spread

  • Renal failure limiting antifungal use

22. OSCE / PRACTICAL STATIONS (COMPLETE)

22.1 SPOTTER

  • Black nasal eschar in diabetic patient
    Diagnosis: Invasive fungal rhinosinusitis (likely mucormycosis)

22.2 IMAGING STATION

  • CT PNS showing hyperdense sinus contents
    Interpretation: Fungal sinusitis

22.3 EMERGENCY COUNSELLING

  • Explain life-threatening nature

  • Need for urgent surgery + IV antifungals

  • Possible vision loss

22.4 PROCEDURAL VIVA

  • Indications of FESS

  • Goals of debridement

  • Antifungal therapy duration

23. LONG & SHORT CASES (UNIVERSITY STYLE)

23.1 LONG CASE

History

  • 55-year-old diabetic

  • Facial pain, nasal obstruction

  • Black nasal crusts

  • Sudden vision loss

Examination

  • Pale necrotic nasal mucosa

  • Reduced ocular movements

Diagnosis

  • Acute invasive fungal rhinosinusitis

Management

  • IV liposomal amphotericin B

  • Emergency surgical debridement

  • Glycemic control

23.2 SHORT NOTES

  • Allergic fungal rhinosinusitis

  • Mucormycosis

  • Fungal ball

  • Angioinvasion

24. MCQs (EXAM-ORIENTED)

1. Broad non-septate hyphae with right-angle branching are seen in:
A. Aspergillosis
B. Candidiasis
C. Mucormycosis
D. Cryptococcosis
Correct Answer: C

2. Drug of choice for invasive fungal sinusitis:
A. Fluconazole
B. Amphotericin B
C. Ketoconazole
D. Itraconazole
Correct Answer: B

3. Most common predisposing factor for mucormycosis:
A. Asthma
B. Hypertension
C. Diabetes mellitus
D. Smoking
Correct Answer: C

25. VIVA QUESTIONS (RAPID-FIRE)

  • Classify fungal rhinosinusitis

  • Difference between invasive and non-invasive disease

  • Why diabetics are prone to mucormycosis

  • Role of MRI

  • Complications of invasive fungal sinusitis

26. EXAMINER TRAPS (VERY IMPORTANT)

  • Assuming all fungal sinusitis needs antifungals

  • Delaying surgery in invasive disease

  • Missing early signs like numbness or mild vision changes

  • Treating AFRS with antifungals alone

27. PREVENTION (HIGH-YIELD)

  • Strict diabetes control

  • Judicious steroid use

  • Early treatment of sinusitis

  • Regular follow-up post-COVID patients

  • Good nasal hygiene

28. CLINICAL PEARLS (EXAM GOLD)

  • Black nasal eschar = invasive fungal sinusitis until proven otherwise

  • Ethmoid → orbit; sphenoid → brain

  • AFRS shows allergic mucin, not invasion

  • Surgery + antifungals save lives

  • Delay kills tissue, vision, and life

Written And Compiled By Sir Hunain Zia (AYLOTI), World Record Holder With 154 Total A Grades, 7 Distinctions And 11 World Records For Educate A Change MBBS 4th Year (Fourth Year / Professional) Otorhinolaryngology (ENT) Free Material

Hunain Zia

Hunain Zia has previously achieved considerable success in the high-school educational stream, gaining a massive 154 Total A Grades and 7 Major Distinctions, a process in which he broke/ set 11 different world records, including the most A grades ever achieved, most subjects ever appeared in, most distinctions, gaining distinctions across two separate boards (Pearson Edexcel and CAIE) within the same year/ ever, and even 19 hours of constant examination. All records stand intact today. Hunain pursued his Honors Accounting Degree from the prestigious Bentley University, and then completed an LLB (in Honors) from University of London. Currently, he manages multiple social and commercial projects, has founded digital streams and works tirelessly in the education sector.

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