Upper Resp Tract Infections

Question 1

Give some general symptoms of upper resp tract infections

Answer 1

Sudden onset fever
Headache, high temp
Generalised aching
Sore throat, red pharynx
Cough
Prostration

Question 2

What are the common URT infections?

Answer 2

Common cold (coryza)- may be identical to Group A strep infection
Influenza
Sinusitis
Pharyngitis
Otitis media, externa and mastoiditis

Question 3

Describe influenza- inc the complications, treatment and prevention

Answer 3

Influenza: Sudden onset, fever, myalgia, headache
Complications: pneumonia
Treatment: oseltamivir
Prevention: vaccine
3 types of influenza virus: A, B and C. A is most common and most serious

Question 4

What is the difference between genetic/antigenic drift and genetic/antigenic shift?

Answer 4

Point mutations in RNA =antigenic drift, a reason why each winter we need a new vaccine

Genetic reassortment = big change in RNA =antigenic shift
Causes pandemic as new strain of virus
Pandemics = rarer, few times per century, higher attack rate and case fatality

Question 5

Describe pharyngitis- its causes, investigations and diagnosis

Answer 5

Viral causes: EBV

Bacterial causes: strep pyogenes (group A strep), group C strep, arcanobacterium, diphtheria
Investigations: throat culture, monospot, EBV serology, ASOT (for group A strep)
Diagnosis of group A strep: Beta haemolytic culture, reacts with group A antiserum
Bacitracin sensitive

Question 6

Describe acute epiglottitis- its cause, symptoms and treatment

Answer 6

Caused by haemophilus influenzae b (Hib):
Severe resp distress, fever, drooling, patient won’t lie down, stridor
Thumbprint appearance of throat on x ray
Usually affect approx. 6m-6 years
Treatment: intubate ASAP, ceftriaxone antibiotics

Question 7

Croup - causes, symptoms, treatment

Answer 7

Croup: usually affects 3 months- 3 years
Parainfluenza virus (and others)
Severe barking cough, inspiratory stridor
Inflammation and oedema of larynx and trachea
Subglottic region is the least distensible part of airway so its prone to obstruction
Treatment: Steam, single dose steroids, may need hospital admission and ventilation

Question 8

Describe Community acquired pneumonia- causes, investigations

Answer 8

Strep. Pneumoniae = commonest cause.
Common viral cause =influenza
Legionella, staph A, chlamydia more atypical causes.

Lab investigations: lower resp sputum (not salivary). Blood cultures, serum
Urine antigen test: fast, unaffected by antibiotics, better than culture. BUT not sensitive

Question 9

Give some symptoms of Community acquired pneumonia

Answer 9

Worsening chest pain on one side
Pain on inspiration
Coughing, small amount purulent sputum
Violent shaking episode
High temp
Tachycardia
Hypoxia
Dull Lung base
High WCC, CRP

Question 10

Describe the management of CAP

Answer 10

Management:
35% oxygen to improve saturation, IV fluid, ibuprofen for pain
Antibiotics: IV benzylpenicillin, clarithromycin
Pneumococcal antigen positive and cultures negative eventually switched to oral doxycycline

Question 11

Explain how COPD may be exacerbated by respiratory infections

Answer 11

COPD patients have chronic sputum production, and chronic colonisation of pathogens such as pneumococcus, haemophilus influenzae. This exacerbates COPD
Investigations: cultures never positive, UAT not useful, sputum has limited value. So clinical context is important

Question 12

How would you treat a COPD patient with a resp infection?

Answer 12

Treatment:
-Maintain oxygenation
-Treat underlying using amoxicillin, doxycycline
-Treat airway obstruction using bronchodilators, corticosteroids
-Hydration/nutrition