Upper respiratory tract infections
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This is a common condition seen in community practice. Patients
have fever and a painful, infected throat that may have visible pus
or exudate. Regional lymph nodes may be painful and enlarged.
Bacterial and fungal causes includeStreptococcus pyogenes
gonorrhoeae and Candida. Corynebacterium diphtheriae infection should
be considered if there is an appropriate travel or vaccination history
). Streptococcal infection may be complicated by peritonsillar
abscess (quinsy), bacteraemia, rheumatic fever or nephritis.
Otitis media and sinusitis
- Most infections in adults are viral so symptomatic treatment is
- Penicillin V or a macrolide is given if bacterial infection is suspected
or proven by near-patient testing.
- Ampicillin should be avoided as it may provoke a rash with
Epstein-Barr virus (EBV) infection.
- Tonsillectomy or adenoidectomy may reduce the frequency of
episodes of pharyngitis or otitis media in patients with quinsy or
recurrent otitis media.
- Infection occurs when the Eustachian tube or sinuses are
occluded by inflammation.
- Children under 7 years are especially prone because the Eustachian
tube is short, narrow and nearly horizontal.
- Streptococcus pneumoniae, S. pyogenes, Haemophilus influenzae,
Moraxella catarrhalis and the more recently recognized Alloiococcus
otitidis are the commonest causative organisms.
- Presentation is with local pain and fever.
- With sinusitis, the pain may be worse with head movement and
in the evening.
- Ear infection may be complicated by perforation, recurrent or
chronic infection or the development of 'glue ear' (sterile mucus
within the middle ear).
- Rarely, acute meningitis or mastoiditis can complicate severe
- Diagnosis is clinical: an auroscope may show retrotympanic
fluid levels, an inflamed tympanic membrane or a purulent discharge
associated with perforation.
- Treatment depends on reducing the mucosal swelling, promoting
drainage of the fluid and encouraging the recirculation of air.
- Appropriate antibiotic therapy is used in more severe cases.
This infectious swelling of the epiglottis may threaten the airway.
type b was a common cause until vaccination became
available. Infection with S. pyogenes
causes some cases, usually in
Lower respiratory tract infections
- Presentation is with sore throat and high fever.
- Stridor and drooling are usually present.
- Throat examination should be avoided because it may precipitate
acute respiratory obstruction.
- Treatment is with parenteral third-generation cephalosporins.
- Emergency tracheostomy may become necessary.
Infections of the lower respiratory tract are an important cause of
morbidity and mortality worldwide and a major cause of death in
children under 5 years.
Predisposing factors include:
- chronic obstructive pulmonary disease;
- diabetes mellitus;
- immunosuppressive therapy;
The bacterial causes are illustrated and many viruses cause
primary viral pneumonia (e.g. influenza and SARS coronavirus).
Others cause damage to the lower respiratory tract, permitting
secondary bacterial pneumonia.
- Fever and a cough.
- Purulent sputum production that may be blood stained.
- Some pathogens (e.g. Mycoplasma) rarely cause productive
- Pleural inflammation causes sharp chest pain that is worse on
- Signs of systemic infection, such as myalgia, malaise and weakness,
may be present.
- In elderly people, mental confusion is common even when specific
symptoms and signs are slight.
- Pleural and pericardial spread.
- Staphylococcus aureus infection can be complicated by lung cavitation
Diagnostic samples include:
- expectorated sputum;
- induced sputum;
- bronchoalveolar lavage (especially for suspected tuberculosis or
for immunocompromised patients).
Rapid diagnostic techniques may be possible, such as urinary
antigen detection for S. pneumoniae
and Legionella pneumophila
Multiplex nucleic acid amplification tests (NAATs) are available
for all respiratory pathogens and can be performed quickly enough
to inform treatment choice.
Management and Prevention
- Appropriate antibiotic therapy should be started as soon as
- Severe, community-acquired pneumonia requires hospitalization
with intravenous antibiotics (e.g. a third-generation cephalosporin
- Milder infections can be treated with oral therapy, often with
amoxicillin and/or a macrolide, although quinolones such as moxifloxacin
are also used. As β-lactam resistance is common in H.
influenzae, patients with chronic obstructive pulmonary disease
should be treated with an appropriate agent (e.g. co-amoxiclav or
- Treatment of hospital-acquired pneumonia may require agents
that are active against Enterobacteriaceae and Pseudomonas (e.g.
ciprofloxacin or ceftazidime).
- Supportive therapy may include bed-rest, oxygen, rehydration,
physiotherapy and ventilation if needed.
Infective exacerbations of cystic fibrosis are often initially with
; later infections with Pseudomonas and Burkholderia
cepacia require specialist management with detailed culture and
susceptibility testing that allows the optimization of antimicrobial
therapy. This should be coupled with intensive postural drainage