Allergic Rhinitis and Immune Response Quiz

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Questions and Answers

What is the primary function of percutaneous and intradermal testing in patients?

To evaluate heart rhythm

To detect specific IgE antibodies (correct)

To assess lung function

To measure blood pressure

Which of the following treatments is key in managing allergic rhinitis?

Allergen avoidance (correct)

Medication only

Immunosuppression

Surgical intervention

Which cytokines are specifically produced during the immediate release of inflammatory mediators?

IL-4, IL-13 (correct)

TNF-α, IGF-1

IL-1, IL-6

IFN-γ, IL-10

What is one of the limitations of the RAST (radioallergosorbent test)?

There is no uniformity as to what is considered positive Signup and view all the answers

Which condition is characterized by symptoms such as wheezing and itchy runny nose due to IgE-mediated reactions?

Allergic Rhinitis Signup and view all the answers

What is a common trigger for seasonal allergic rhinosinusitis?

Grass pollen Signup and view all the answers

Which of the following is NOT a known risk factor for allergic rhinitis?

Consumption of processed foods Signup and view all the answers

Which T helper cell type is primarily responsible for stimulating the production of IgE in allergic responses?

Th2 cells Signup and view all the answers

Which atopic condition is associated with a severe, systemic allergic reaction?

Anaphylaxis Signup and view all the answers

Which of the following statements regarding tissue eosinophils is true?

They are involved in local inflammation and tissue damage. Signup and view all the answers

What characterizes the late phase of an IgE-mediated allergic reaction?

Release of arachidonic acid metabolites leading to congestion Signup and view all the answers

What factor is likely to increase the risk of developing allergies in a child?

Being an only child Signup and view all the answers

How does early life exposure to antibiotics relate to allergic rhinitis?

It increases the risk of developing allergic rhinitis. Signup and view all the answers

Which physical examination finding might indicate allergic conjunctivitis?

Conjunctival papillae Signup and view all the answers

Which symptom is NOT typically associated with rhinitis?

Headaches Signup and view all the answers

What is the role of skin tests in diagnosing atopic conditions?

To demonstrate IgE presence Signup and view all the answers

What is the role of the priming effect in allergic reactions?

It allows for a quicker response upon subsequent exposures to the same antigen. Signup and view all the answers

Which cytokines are associated with the Th2 response in allergy production?

IL-4, IL-5, IL-13 Signup and view all the answers

Which environmental irritant is known to worsen symptoms of allergic rhinitis?

Tobacco smoke Signup and view all the answers

Which environmental factor is primarily assessed in the history of an atopic patient?

Presence of pets in the home Signup and view all the answers

During which seasonal period is pollen from weeds most likely to be a trigger for allergic rhinitis?

Fall Signup and view all the answers

Study Notes

Rhinitis: Allergic and Non-Allergic

Rhinitis is characterized by one or more nasal symptoms including congestion, rhinorrhea, sneezing, and itching.
It is classified as either allergic or non-allergic.
Allergic and non-allergic rhinitis can both be present in 44-87% of patients.

Allergic Rhinitis: Objectives

Understand the difference between allergic and non-allergic rhinitis, including mechanisms and treatments.
Know how to diagnose and treat rhinitis.
Know the mediators of allergic rhinitis.
Understand how immunotherapy alters the immune system (not all mechanisms).
Know what anti-IgE is and how it can affect allergic diseases.
Understand the immunology of allergic diseases.
Know the IgE-mediated conditions.
Define triggers of allergic rhinitis and how to avoid them.

Allergic Rhinitis: Burden

Affects 10-30% of adults and up to 40% of children worldwide.
Worldwide prevalence is increasing.
Impacts quality of life, leading to reduced work productivity and lost school days.
Direct costs to individuals and society in the United States are $3-4 billion per year.
Individuals with allergic rhinitis (AR) spend an average of $650 annually on AR-related medical and pharmacy services.

Allergic Rhinitis: Risk Factors

Family history of atopic disease
Serum IgE > 100 IU/mL before age 6
Higher socioeconomic status
Exposure to environmental irritants (pollution, tobacco smoke)
Early life exposure to antibiotics
Positive skin prick test
Indoor allergen sensitization (6 months - 2 years old)
Pollen sensitization (2-7 years old)

Allergic Rhinitis - Pathophysiology

IgE-mediated reaction to inhaled allergens.
Allergen interacts with IgE on mast cell surfaces, triggering degranulation.
Early phase: histamine release causing sneezing, rhinorrhea.
Late phase: arachidonic acid metabolites causing congestion.
Food allergy rarely causes isolated nasal symptoms.
Tissue eosinophils contribute to local inflammation and damage.
Repeated antigen exposure reduces the amount needed to induce an immediate response (priming).
Air pollutants also affect priming.

Definition- Rhinitis

Rhinitis is defined by one or more nasal symptoms: congestion, rhinorrhea, sneezing, or itching.
Classified as either allergic or non-allergic.
Differential diagnoses should include chronic rhinosinusitis, nasal polyps, cerebrospinal fluid leaks, and structural nasal abnormalities.

Seasonal Allergic Rhinitis: Patterns of Symptoms

Spring: trees
Summer: grasses
Fall: weeds (especially ragweed)
Perennial: cockroaches, dust mites, pets, mold

Globally Important Sources of Allergens

House dust mites
Grass, tree, and weed pollen
Pets
Cockroaches
Molds

CD4+ T helper cells

Th1: "Anti-allergy" cell. Stimulates phagocyte-mediated defense against intracellular antigens (IFN-γ).
Th2: "Allergy-producing" cell. Stimulates IgE, eosinophils, and mast cells in response to extracellular antigens. Downregulates Th1 response (IL-4, IL-5, IL-13).

The Hygiene Hypothesis

Link between decreased exposure to infections in childhood and increased risk of allergies.
Older siblings typically have more infections and Th2 stimuli , and so are less likely to develop allergies.
Children with fewer infections (only child) have less Th2 stimuli and increased risk for allergies.

Factors Favoring Th1 and Th2 Phenotypes

Th1: Presence of older siblings, early exposure to day care, tuberculosis, measles, or hepatitis A infection, rural environment.
Th2: Widespread use of antibiotics, Western lifestyle, urban environment, diet, sensitization to house-dust mites and cockroaches.

Atopic Conditions

Anaphylaxis, allergic rhinosinusitis, allergic conjunctivitis, asthma, atopic dermatitis, urticaria/angioedema, food allergies, drug allergies, stinging insect allergies, latex allergy.

Approach to the Atopic Patient: History

Onset of symptoms (typically by age 10)
Character, duration, frequency, and severity of symptoms.
Temporal nature of symptoms (seasonal or perennial).
Environmental nature of symptoms (home, school, work).
Family history (maternal and paternal).

Approach to Patient with Atopy: Physical Exam

Skin: dermatographism, urticaria, dermatitis
Eyes: allergic shiners, conjunctival papillae
Nose: pale/bluish mucosa, clear mucus, creases, polyps
Lungs: wheeze, increased E/I ratio

Approach to Patient with Atopy: Primary Tests

Skin tests: demonstrate the presence of specific IgE antibodies to aeroallergens, foods, insect venoms, and PCN. Percutaneous and intradermal testing.
Patients must be off of antihistamines, tricyclics, and beta-blockers. These tests use controlled (+) and (-) samples to determine results.
RAST (radioallergosorbent test): measures specific IgE. Expensive, less sensitive than skin tests, and results can differ significantly.

Skin Testing

Skin tests are a method to diagnose allergies
Specific allergens are placed on the patient's skin

IgE-dependent Release of Inflammatory Mediators

IgE binds to mast cell receptors.
Triggers granule contents release after allergen exposure: histamine, TNF-α, proteases, heparin, etc.
Release from mast cells results in symptoms of sneezing, nasal congestion, itchy, runny nose, watery eyes, and wheezing.

Allergic Rhinitis: Treatment (1) - Allergen Avoidance

Dust mites: reduce humidity, wash bedding regularly, encase mattresses and pillows in allergen-proof covers.
Cockroaches: clean cockroach reservoirs, pest management.
Furry pets: exclude from utilized rooms, or washing pets, HEPA air filters and vacuuming, etc.
Mold/fungi: reduce indoor moisture, minimize, good ventilation, dehumidifier

Allergic Rhinitis: Treatment (2)

Intranasal Corticosteroids
Intranasal Antihistamines
Intranasal Anticholinergics
Oral Antihistamines
Nasal lavage
Intranasal cromolyn
Oral and Topical Decongestants (limited use recommended)

Allergic Rhinitis: Treatment (3) -Allergen-Specific Immunotherapy

Repeated allergen administration.
Results in immunologic changes such as regulatory T lymphocytes, shift of immunity to type 1, and eventual IgG reduction.
Subcutaneous or sublingual tablets are commonly used.
Risk of anaphylaxis with subcutaneous injections.

Recommendations

Allergen immunotherapy should be prescribed by an allergy and immunology specialist.

Allergen Immunotherapy and Immune Tolerance

Shifts immune response from Th2 to Th1.
Suppresses seasonal rise in specific IgE.
Increases specific IgG1 and IgG4.
Increased levels of IgG and IgA in nasal secretions.
Reduced reactivity and sensitivity of basophils to antigen.
Decreases mast cells/eosinophils in target organs.
Decreases early and late allergic responses.
Maintains symptom improvement after stopping therapy.
May affect the natural course of allergic disease.
May prevent asthma development in 40% of children

Non-allergic Rhinitis (NAR): Background

Chronic inflammation of nasal mucosa without evidence of allergies (no allergic sensitization).
Often idiopathic (no known cause) or vasomotor rhinitis.
Predominant symptoms are nasal congestion and rhinorrhea;
Associated symptoms: facial/ear pain, pressure, sneezing, post-nasal drip, poor sense of smell, throat clearing, and cough.
Nasal and/or oral pruritus and ocular symptoms less common.

Non-allergic Rhinitis

17-52% of adult rhinitis cases.
20 million affected Americans.
Onset is typically adulthood.
70% present after 20 years of age. - Female predominance (2:1)
Symptoms triggered by nonimmunologic stimuli: cold/dry air, irritants, cigarette smoke, cleaning products, or strong odors.

Non-allergic Rhinitis: Diagnosis

No pathognomonic symptoms.
Swollen turbinates or reactive upper airway dysfunction may be observed.
Assessment of irritant triggers. - Non-specific nasal hyper-reactivity to methacholine, histamine, capsaicin, or cold/dry air.
Allergen skin/serologic testing negative or not correlating with symptoms.
Commonly neutrophilic, eosinophilic, or paucigranulocytic inflammatory reactions observed.

Non-Allergic Rhinitis with Eosinophilia (NARES)

Type of inflammatory Non-allergic Rhinitis.
Nasal secretions contain > 25% eosinophils.
Approximately 12-25% of NAR cases.
Increased nasal symptoms and anosmia.
Responsive to intranasal glucocorticoids.

Gustatory Rhinitis

Clear rhinorrhea following food ingestion (immediately).
Hot/spicy foods are common triggers; any food can elicit a response.
Food stimulates afferent sensory nerves in the oropharynx which then activate parasympathetic efferent nerves in the nasal mucosa that increase nasal secretions and cause congestion.
Rarely associated with food allergies, unless anaphylaxis is occurring.

Gustatory Rhinitis: Treatment

Avoid offending foods.
Initial treatment is intranasal anticholinergic agents (Ipratropium Bromide).
Using this agent prophylactically (immediately prior to eating) is most effective.
Combination of intranasal ipratropium bromide & nasal corticosteroid may be more effective than either medication alone.

Rhinitis Medicamentosa

Rebound nasal congestion caused by overuse of intranasal alpha-adrenergic drugs (oxymetazoline or phenylephrine) or cocaine.
In the US, these drugs are labeled with a 3-day treatment warning.
Diagnosis is made via complete history and exam.
Nasal mucosa is often erythematous, granular, and show punctate bleeding.
Topical decongestant use cessation is first line of treatment to resolve this condition.

Summary

Rhinitis can be allergic, non-allergic, or both.
Non-allergic rhinitis (NAR) isn't caused by IgE & is treated with intranasal steroids.
Allergic rhinitis (AR) is primed as the allergen season progresses (fewer allergens trigger responses later in the season).
AR treatment includes antihistamines, nasal steroids, and immunotherapy.

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Description

Test your knowledge on allergic rhinitis, its management, and underlying immunological principles. This quiz covers key concepts like cytokines, IgE responses, and various diagnostic tests related to allergies. Perfect for students studying immunology or allergy-related healthcare.