RISK FACTORS : Crowded living conditions, Inadequate immunization. In the USA, 22-62% of
people age 18 to 39 years and 41-84% of people over 60 years of age lack protective levels of antibody. Lower socioeconomic status
APPROPRIATE HEALTH CARE :
• Inpatient, initially hospitalized in unit which can monitor cardiac and respiratory status. (Must act on presumptive diagnosis because therapy cannot wait for culture confirmation).
• Isolation until cultures on two consecutive days are negative. The first culture must be taken at least 24
hours after the cessation of antibiotic therapy.
GENERAL MEASURES :
• Have intubation or tracheostomy readily available. For laryngeal disease, laryngoscopy is desirable.Intubation or tracheostomy should be considered early for laryngeal disease.
• Avoid hypnotics and sedatives while monitoring respiratory status
• Physical therapy in convalescence for range of motion exercises to prevent contractions
DRUG(S) OF CHOICE :
Both antitoxin and antibiotics are needed for non-cutaneous diphtheria
• Diphtheria antitoxin, equine: Use 20,000 to 40,000 units of antitoxin for laryngeal or pharyngeal disease of less than 48 hours duration, 40,000 to 60,000 units for nasopharyngeal lesions, 80,000 to 120,000 units for extensive disease of 3 or more days duration or swelling of the neck (bull neck). Administer antitoxin by IV infusion over 60 minutes and/or by intramuscular injection. Some experts recommend treating cutaneous
disease with 20,000 to 40,000 units of antitoxin while others doubt its value when there are no signs of
systemic disease. Antitoxin is obtained from the CDC.
• Erythromycin parenterally or orally, 40-50 mg/kg/day; maximum of 2 grams/day for 14 days
ALTERNATIVE DRUGS:
• Penicillin G intramuscularly, 100,000 to 150,000 units/kg/day in four divided doses up to 600,000 units
per day
• DL-carnitine 100 mg/kg/day given bid po in children for 4 days in myocarditis (experimental)
PATIENT MONITORING :
. ECG, cardiac enzymes and respiratory status. Serial ECG 2-3 times per week for 4-6 weeks to detect
myocarditis.
. Elimination of the organism should be documented by three negative cultures at least 24 hours apart. The fi rst culture should be at least 24 hours after the completion of antimicrobial therapy.
. During convalescence, patients should be immunized against diphtheria because infection does not necessarily confer immunity
PREVENTION/AVOIDANCE :
. Prevention is by immunization:
. Children 6 weeks up to 7 years of age should receive doses at 2, 4, 6 and 15-18 months and 4-6 years of
age with 0.5 mL of DTaP vaccine IM. If the pertussis component is contraindicated then pediatric DT should be used. A booster dose of adult Td (or Tdap) should be given at age 11-12 years.
. Unimmunized persons 7 years of age or older should receive two doses of adult Td 4-8 weeks apart with a
third dose 6-12 months later. 0.5 mL of Td should be given IM.
. Subsequently, booster doses with Td (or Tdap) should be given every 10 years to all individuals without a contraindication. An alternative strategy after the booster at age 11-12 years is a single adult booster at 50 years of age, in addition to following the recommendations for Td boosters in the event of an injury or wound.
. Immunized individuals may develop diphtheria but their course is milder; immunization protects against the toxin, not infection or microbial carriage in the nose, pharynx or skin
. Disinfect all articles in contact with patient
. Close contacts should be cultured and given antibiotic prophylaxis regardless of immunization status.
Previously immunized contacts should receive a booster of diphtheria toxoid unless vaccinated within last 5 years. Unimmunized contacts should begin the series. Erythromycin prophylaxis for 7 days.
POSSIBLE COMPLICATIONS :
. Myocarditis (in 10-25%) may occur early
. Cranial and peripheral neuropathy (2-6 weeks after onset)
. ECG abnormalities in two-thirds of patients, including: bundle branch block, tachycardia, atrial or ventricular
fibrillation, extrasystoles
. Right sided heart failure
. Local paralysis of soft palate and posterior pharynx demonstrated by regurgitation of fl uids through the nares
. Peripheral and cranial neuropathy affecting primarily motor nerve functions. Motor dysfunction starts proximally and extends distally. Usually slowly resolves.
. Syndrome like Guillain-Barre
EXPECTED COURSE/PROGNOSIS :
. < 5% mortality rate
. Prognosis guarded until recovery
. 5-10% persistence in nasopharynx in convalescing patients