Chronic Rhinosinusitis Flashcards
√What are the etiologic factors for the development of sinusitis? 10
A. INFECTIOUS
1. Viral
2. Bacterial
3. Fungal
B. IMMUNE
1. Congenital
2. Acquired
3. Allergic
C. LOCAL
1. Craniofacial anomalies (choanal atresia, VPI, cleft palate)
2. Trauma
3. Surgery
4. Dental
5. Ciliary
6. Anatomic
√What are the anatomic variations influencing the incidence of sinusitis? 8
- Septal deviation and spur
- Concha bullosa
- Paradoxical middle turbinate (inferomedially curved middle turbinate edge with the concave surface facing the nasal septum, usually occurs bilaterally)
- Prominent Ethmoidal bulla
- Pneumatization or deviation of the uncinate plate
- Prominent agger nasi cells
- Complex frontal cells - supra-aggar/bullar
- Infraorbital ethmoid cell (Haller cell)
√What 7 histologic changes are seen in polyps/CRS?
Classification of Nasal polyposis:
1. Edematous, eosinophilic (most common, 85%)
2. Fibroinflammatory
3. Glandular
Features of edematous, eosinophilic polyps:
1. Edema + scattered fibroblasts
2. Infiltrates of inflammatory cells (e.g. neutrophils, mast cells)
3. Epithelial ulceration
4. Squamous metaplasia
5. Epithelial hyperplasia
6. Goblet cell hyperplasia
7. Eosinophilic infiltrates
I’m EGF Sue ME
√What are the etiologic factors for nasal polyps? 7
A. Inflammation
1. Nasal mastocytosis (increased mast cells in nasal mucosa)
2. Chronic infection
3. Allergy, including fungal
4. Samter’s triad
B. Ciliary problems
1. Cystic fibrosis
2. Kartegener’s syndrome
3. Young’s syndrome (bronchiectasis, rhinosinusitis, and reduced fertility)
Can also be divided as:
1. Eosinophilic: eGPA, AERD, Allergy, AFRS
2. Non-eosinophilic: CF, Antrochoanal polyp, Kartageners
List 6 different conditions that may be associated with nasal polyposis.
- Atopy (atopic dermatitis, asthma, allergic rhinitis)
- AERD
- NARES
- PCD
- Cystic Fibrosis
- eGPA (Curg-Strauss Syndrome)
Discuss two types of grading systems for polyp size
0-3 Grading:
1. Grade 0: No visible polyps
2. Grade 1: Polyps confined to middle meatus
3. Grade 2: Polyps extending beyond middle meatus but not obstructing nasal cavity
4. Grade 3: Polyps completely obstructing nasal cavity
0-4 Grading (Meltzer)
1. Grade 0: No visible polyps
2. Grade 1: Polyps not reaching inferior border of middle turbinate
3. Grade 2: Polyps reaching inferior border of middle turbinate
4. Grade 3: Polyps extending below middle turbinate, not obstructing nasal cavity
5. Grade 4: Polyps completely obstructing nasal cavity
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What are the CT and MRI findings of nasal polyps?
- CT: Low density
- MRI:
- T1 Hypointense
- T2 Hypertense (high water content)
What are the conditions that are associated with CRS?
- COPD
- N-ERD (NSAID-Exacerbated respiraotry disease)
- Hypogammaglobulinemia
- GERD
- Asthma
What is the difference between Eosinophilic CRS and Non-eosinophilic CRS?
- eCRS and Non-eCRS = determined by the histologic quantification of the numbers of eosinophils
- Number per high powered field = 10/hpf (400x)
Tissue eosinophil level and inflammation are closely related to treatment response
- 10-100/hpf in >2 areas of >100/hpf in >2 areas
What are the associations between CRS, polyps, and asthma?
- 20% of CRS have polyps
- 40% of CRS have asthma (Canadian guideline)
- 50% of polyps have asthma (35% of which have Samter’s triad)
- 10-20% of polyps have Samter’s triad
- 7% of asthma have polyps
What are the types of inflammatory responses?
- Type 1: Target viruses
- Type 2: Target parasites - characterized by IL-4,-5,-13; activation and recruitment of eosinophils and mast cells
- Type 3: Target extracellular bacteria and fungi
What are 4 groups of mediators important in CRS and asthma?
- Cells: Eosinophils, Th2 lymphocytes
- Cytokines: Interleukins (IL-1B predominant; also IL-4, 5, 13), PAF, TNF
- Prostaglandins and Leukotrienes
- Acute sinusitis - IL4 and 6
Discuss IL-4:
1. What does it do? List 5 things
- Stimulation of activated B-cell and T-cell proliferation
- Differentiation of B cells into plasma cells
- Key regulator in humoral and adaptive immunity
- Induces B-cell class switching to IgE
- Upregulates MHC class II production
List 5 functions of IL-5
- Stimulates B-cell growth
- Increase immunoglobulin secretion - primarily IgA
- Mediiator in eosinophil activation
- Two major signaling pathways of IL-5 in eosinophils:
- A. Activates Lyn, Syk, and JAK2
- B. Propagates signals through the Ras-MAPK and JAK-STAT pathways
List 6 functions of IL-13
Similar to IL-4
- Central regulator in IgE synthesis
- Goblet cell hyperplasia
- Mucous hypersecretion
- Airway hyperresponsiveness
- Fibrosis up-regulation
- A mediator of allergic inflammation in asthma
Discuss the Canadian Diagnostic Criteria for Chronic Rhinosinusitis. Outline the full criteria.
CANADIAN DIAGNOSTIC CRITERIA
Needs ALL THREE of the following:
1. 2 or more of CPODS:
a/ Congestion
b/ Pressure
c/ Obstruction
d/ Discharge (purulent rhinorrhea)
e/ Smell changes (hyposmia/ansomia)
- Lasting for more than 8-12 weeks
- Objective findings of inflammation:
a/ Endoscopic findings; OR
b/ CT findings (mucosal changes within OMC and/or sinuses)
ENDOSCOPIC SIGNS OF:
1. Nasal polyps, and/or
2. Mucopurulent discharge primarily from middle meatus, and/or
3. Edema/mucosal obstruction primarily in middle meatus
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Regarding CRS: How has it been historically classified/divided into?
CRS has historically been divided into:
1. CRSwNP: Th2 predominant (more allergic)
2. CRSsNP: Th1 predominant
3. Then further divided into eosinophilic vs. non-eosinophilic
4. Then further divided into allergic fungal vs. non-allergic fungal
*This has changed from EPOS Classification in 2020 (previous classification too non-specific)
Discuss the EPOS classification 2020 of Chronic Rhinosinusitis
PRIMARY CRS:
1. Localized = unilateral
a/ Type 2 = e.g. AFRS
b/ Non-Type 2 = e.g. isolated sinusitis
2. Diffuse = bilateral
a/ Type 2 = e.g. CRSwNP, AFRS, CCAD (Central Compartment Atopic disease - variant of CRSwNP associated with inhalant allergy, characterized by polypoid changes in the central compartment ie. superior nasal septum, middle turbinates, and/or superior turbinates)
b/ Non-type 2 = non-eosinophilic CRS
SECONDARY CRS:
1. Localized = unilateral
a/ Local pathology, such as:
- Fungal ball
- Odontogenic sinusitis
- Sinonasal tumor
2. Diffuse = bilateral
- Mechanical = e.g. PCD or CF
- Inflammatory = e.g. GPA, eGPA
- Immunity = e.g. selective immunodeficiency
Discuss all the known contributing factors to chronic rhinosinusitis 6
A. HOST FACTORS
1. Genetic predisposition
2. Structural (anatomic) factors
3. Defects in innate or adaptive immunity
B. MICROBIAL FACTORS
1. Superantigens
- Exotoxins produced by infectious organisms that can activate a larger population of the T-lymphocyte pool
- Especially seen with Staph Aureus
2. Biofilms
- Biofilms are a community of bacteria adherent to a surface
- Extracellular matrix of biofilm protects against host defence systems
C. ENVIRONMENTAL FACTORS
1. Smoking
2. Allergies
3. Pollution
What systemic conditions predispose to CRS? 8
- Allergic rhinitis
- Recurrent viral URTIs
- Dental infections
- Primary ciliary dyskinesia
- Immunocompromised (HIV, IgG deficiency)
- Poor nutrition
- Chronic steroid use
- Diabetes
What are the most common organisms in Chronic Rhinosinusitis?
- Staph Aureus
- Anaerobes
- Fusobacterium
- Peptostreptococcus
- Prevotella
- Porphyromonas
- Enterobacteriaceae - Pseudomonas Aeruginosa
- Most common in Cystic Fibrosis
- More common in nosocomial infection or in immunocompromised host
UNCOMMON:
1. Pneumococcus
2. H. Influenzae
3. Beta-hemolytic streptococci
4. Coag-negative staph
What are 7 histopathologic findings in CRS?
- Submucosal gland formation
- Major basic protein deposition
- Eosinophilic and lymphocytic infiltration
- Goblet cell hyperplasia
- Mucous hypersecretion
- Abnormal Basement membrane thickening
- Subepithelial edema/fibrosis
SMEGMAS
How does sinonasal tissue get remodelled in Type 2 CRS?
- Polyp formation
- Epithelial barrier abnormalities - greater permeability
Biologic agents that suppress Type 2 inflammation reverse remodelling and limit recurrence