Chapter 4.6.2 Diphtheria

Diphtheria is a bacterial infection, which can be prevented by immunization. Infection in the upper airway or nasopharynx produces a grey membrane, which, when present in the larynx or trachea, can cause stridor and obstruction. Nasal involvement produces a bloody discharge.

Diphtheria toxin causes muscular paralysis and myocarditis, which are associated with mortality.

Diagnosis

Carefully examine the child’s nose and throat and look for a grey, adherent membrane. Great care is needed when examining the throat, as the examination may precipitate complete obstruction of the airway. A child with pharyngeal diphtheria may have an obviously swollen neck, termed a ‘bull neck’.

     

 

Treatment:

Give 40 000 U diphtheria antitoxin (IM or IV) immediately, because delay can increase the risk for mortality. As there is a small risk for a serious allergic reaction to the horse serum in the antitoxin, an initial intradermal test to detect hypersensitivity should be carried out, as described in the instructions, and treatment for anaphylaxis should be available

Antibiotics

Any child with suspected diphtheria should be given a daily deep IM injection of procaine benzylpenicillin at 50 mg/kg (maximum, 1.2 g) daily for 10 days. This drug should not be given IV.

Oxygen

Avoid using oxygen unless there is incipient airway obstruction.  Signs such as severe lower chest wall indrawing and restlessness are more likely to indicate the need for tracheostomy (or intubation) than oxygen. Moreover, the use of a nasal or nasopharyngeal catheter can upset the child and precipitate obstruction of the airway.

However, oxygen should be given if there is incipient airway obstruction and intubation or a tracheostomy is deemed necessary.

Tracheostomy/intubation

Tracheostomy should be performed, only by experienced staff, if there are signs of incipient complete airway obstruction, such as severe lower chest wall indrawing and restlessness. If obstruction occurs, an emergency tracheostomy should be carried out.  Orotracheal intubation is an alternative, but may dislodge the membrane and fail to relieve the obstruction.

Supportive care

If the child has fever (> 39 °C or > 102.2 °F) that appears to be causing distress, give paracetamol.
Encourage the child to eat and drink. If the child has difficulty in swallowing, nasogastric feeding is required. The nasogastric tube should be placed by an experienced clinician or, if available, an anaesthetist.

Avoid frequent examinations and invasive procedures when possible or disturbing the child unnecessarily.

Monitoring

The child’s condition, especially respiratory status, should be assessed by a nurse every 3 h and by a doctor twice a day. The child should occupy a bed close to the nursing station, so that any sign of incipient airway obstruction can be detected as soon as it develops.

Complications

Myocarditis and paralysis may occur 2–7 weeks after the onset of illness.

Signs of myocarditis include a weak, irregular pulse and evidence of heart failure. Refer to standard paediatric textbooks for details of the diagnosis and management of myocarditis.

Public health measures

The child should be nursed in a separate room by staff who are fully vaccinated against diphtheria.
Give all vaccinated household contacts a diphtheria toxoid booster.
Give all unvaccinated household contacts one dose of benzathine penicillin (600 000 U for those aged < 5 years, 1 200 000 U for those > 5 years). Give them diphtheria toxoid, and check daily for 5 days for any signs of diphtheria.