Diphtheria

Background

• An upper respiratory tract illness caused by Corynebacterium diphtheriae, an anerobic Gram Positive Bacteria
• Children are usually vaccinated with the DPT vaccine

Clinical Features

• Symptoms usually begin 5-7 days post initial infection and are often nonspecific mailaise and fatigue
• Fever of 38°C (100.4°F)
• Cyanosis in severe disease
• Sore throat ± difficulty swallowing
• Hoarseness, cough
• Lymphadenopathy
• "Bull neck" in laryngeal diphtheria
• Dense, grey pseudomembrane covering the posterior aspect of the pharynx
• Croup like cough

Differential Diagnosis

• Strep. Pharyngitis
• Tonsillitis
• Epiglotitis
• Mononucleosis
• Laryngitis
• Acute Bronchitis
• Bacterial Tracheitis
• Oral Thrush
• Viral URI

Workup

• Throat culture will provide definitive diagnosis

Management

• Airborne isolation
• Severe disease with respiratory compromise may require intubation
• Diphtheria antitoxin is not recommended in prophylaxis but can be used to treat confirmed disease
  • Antitoxin will not neutralize toxin that is already fixed to tissues, but it will neutralize circulating (unbound) toxin and will prevent progression of disease
  • Administration should be with an ID specialist at the CDC Emergency Operations Center at (US phone: 770-488-7100)

Treatment Antibiotics

Options

• Erythromycin 40mg/kg/day maximum, 2 gm/day
• Procaine penicillin G daily, IM (300,000 U/day for those weighing 10 kg or less, and 600,000 U/day for those weighing more than 10 kg) for 14 days.

Disposition

• Admission for disease with moderate to severe respiratory symptoms or while awaiting cultures due to high disease suspicion in an unvaccinated host

Exposure Prophylaxis

• For close contacts, especially household contacts, a diphtheria booster, appropriate for age, should be given.

Antibiotics

• Should be given to close contacts and family members

Options:

1. Benzathine Penicillin G
   • 600,000 units for persons younger than 6 years old
   • 1,200,000 units for those 6 years old and older
2. Erythromycin 40 mg/kg/day for children and 1 g/day for adults x 10 days