Respiratory tract infections

Question 1

Definition upper respiratory tract infection

Answer 1

Acute infection which involves the upper respiratory tract (nose, sinuses, pharynx or larynx)

Question 2

URI or URTI causes

Answer 2

• Pharyngitis- inflammation of the pharynx
• Rhinitis - inflammation of the nasal mucosa
• laryngitis - inflammation of the larynx
• sinusitis - inflammation of the nose and paranasal sinuses
• otitis media
• common cold
• diptheria

Question 3

Streptococcal pharyngitis

1. bacteria
2. transmission
3. clinical features
4. investigations
5. treatment
6. complications

Answer 3

1. Bacteria - strep pyogenes (group A beta haemolytic streptococcus), gram positive “strep occurs in a strip”
2. Transmission- commensual of URT, aerosal droplets via direct contact. Seasonal variation
3. Clinical features​
   
   • ​​Tonsilar enlargement
   • purulent exudate with sore throat
   • reactive cervical lymphadenopathy
   • fever and malaisa
4. Investigations- throat swabs for microscopy and culture​
5. Treatment - Oral course of penicillin or erthyromycin if allergic
6. Complications - pert-tonsillar abscess (quinsy), otitis media and sinusitis

Question 4

Diptheria

1. bacteria
2. transmission
3. clinical features
4. investigations
5. treatment
6. complications

Answer 4

1. bacteria- corneybacterium diptheriae, spore forming gram-positive
2. transmission - aerosol spread of droplets from nose and throat
3. clinical features -
   
   • ​​Sore throat from pharyngitis
   • tonsilar enlargement
   • covered with firmly adherant false membrane (exudate from necrosis of mucosal cells due toxin effects)
   • cervical lymphadenoapthy
4. investigations - throat swab for microscopy and culture to identify strain causing infection
5. treatment - Antitoxin given rapidly (before bacteriological confirmation), penicillin or eryhtromycin
6. complications - due to toxin production- myocarditis, palatal paralysis, polyneuropathy

Question 5

Epiglottitis

1. bacteria
2. transmission
3. clinical features
4. investigations
5. treatment

Answer 5

1. bacteria - haemophillus influenzae type B
2. transmission - aerosolized droplets, commensual of the URT but only causes infection when breaches the respiratory tract mucosa
3. clinical features
   
   • ​​fever
   • acute onset of respiratory distress and stridor
   • usually occurs in children <5 years
   • epiglottis is swollen and erythematous
4. investigations - Hib can be isolated from throat swabs and blood cultures for microscopy and culture
5. treatment - second or third generation cephalosporins as 15% resistant to ampicillin. HDU or ICU is best for child to be treated