Respiratory Viruses and Rhinitis

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Questions and Answers

What viruses are responsible for causing winter onset respiratory infections?

Rhinoviruses, coronavirus, and RSV (respiratory syncytial virus)

What is the usual location of influenza infection in the respiratory system?

Back of the nose (pharyngeal area)

What is a common complication of adenovirus infection?

Severe inflammation, which can lead to pus in the conjunctiva and mimic bacterial infection

What is a rare cause of rhinosinusitis in immunocompromised individuals?

Fungal infection Signup and view all the answers

What is a common cause of pharyngitis?

Virus (90% of cases) Signup and view all the answers

What is the occasional incursion into the larynx and trachea that can cause laryngitis?

Organism into the larynx and trachea, brought up by mucociliary escalator Signup and view all the answers

What is the protective mechanism around Haemophilus bacteria that makes them invasive?

Polysaccharide capsule (group B polysaccharide) Signup and view all the answers

What is the importance of quick diagnosis in Epstein-Barr virus infection?

To prevent prolonged symptoms and chronic fatigue Signup and view all the answers

What is the common bacterial cause of sore throat?

Streptococcus pyogenes Signup and view all the answers

What is the typical symptom of streptococcal pharyngitis?

Inflammation of the mucous membrane of the throat, mild fever, headache, and swollen lymph nodes in the throat Signup and view all the answers

What is the complication of streptococcal infection that can lead to heart murmur?

Rheumatic fever Signup and view all the answers

What is the characteristic of the strain of Streptococcus that causes scarlet fever?

They have estrogenic information encoded exotoxins Signup and view all the answers

What is the role of M protein in Streptococcus pyogenes?

It is a major immunogen that rises antibody response Signup and view all the answers

How is Streptococcus pyogenes transmitted?

Through saliva droplet or nasal secretion Signup and view all the answers

What is the treatment for streptococcal pharyngitis?

Penicillin G or erythromycin Signup and view all the answers

What is the incubation period of Streptococcus pyogenes?

2-4 days Signup and view all the answers

Study Notes

Respiratory Infections

Rhinoviruses, coronavirus, and RSV (respiratory syncytial virus) cause winter onset respiratory infections.
Influenza affects the back of the nose (pharyngeal area).
Adenovirus causes severe inflammation, leading to pus in the conjunctiva and mimicking bacterial infection, and can cause laryngitis.

Rhinosinusitis

Rhinosinusitis can be fungal in immunocompromised individuals, such as those with diabetes, and is very rare.
Sinusitis is caused by fluid buildup in the area, allowing organisms to colonize and produce pus.
Anatomical issues affecting drainage and allergies can contribute to chronic sinusitis.
Drainage may be required in cases where the patient cannot manage their sinusitis, resulting in a thick, tenacious membrane.

Pharyngitis

90% of pharyngitis cases are caused by viruses.
The remaining 10% are caused by Group A Streptococcus (GAS).

Laryngitis

Laryngitis is caused by viruses, with occasional incursion of organisms into the larynx and trachea.
Inflammation can occur when the mucociliary escalator is damaged, leading to the proliferation of organisms like staph, strep, Moraxella, and Haemophilus.

Haemophilus

Haemophilus has different strains, including one with a polysaccharide capsule (group B polysaccharide).
Invasive Haemophilus can cause meningitis, which is addressed by the influenza type B vaccine.

Epstein-Barr Virus

Epstein-Barr virus causes glandular fever and infectious mononucleosis.
The first growth is in the throat, and quick diagnosis is essential to prevent prolonged symptoms and chronic fatigue.

Streptococcal Disease

Streptococcal disease is caused by invasive, gram-positive cocci, including S.pyogenes, which causes streptococcal pharyngitis (strep throat).
S.pyogenes produces little pus due to cytotoxin, which breaks down inflammatory cells.
A swab can be sent to the lab to grow the causative organism, and treatment may involve lancing and draining abscesses.

Rheumatic Fever

Rheumatic fever is a post-infection complication caused by cell surface antigens similar to human cell surface antigens.
The immune response to the invading pathogen results in antibodies that cross-react with host tissues, leading to autoimmune disease and tissue destruction.
Symptoms may include heart murmurs, which can be evidenced by a whooshing or swooshing sound.

Scarlet Fever

Scarlet fever follows infection with streptococcus, particularly virulent strains that encode exotoxins.
The rash begins on the chest and spreads to the rest of the body after a 2-day incubation period.
The pathogenesis of scarlet fever involves the production of streptolysins (toxins) that lyse red cells and white blood cells, leading to beta-haemolysis.

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Description

This quiz covers the causes of rhinitis and respiratory infections, including rhinovirus, coronavirus, RSV, parainfluenza, and adenovirus. It also touches on sinusitis and fungal infections in immunocompromised individuals.