-IBIS-1.5.0-
tx
respiratory system
diphtheria
diagnoses

definition and etiology

definition:
Corynebacterium diphtheriae causes this contagious disease which is characterized by the formation of a fibrous pseudomembrane in the respiratory airway. Heart and neural tissue damage may occur as a result of exotoxins.

etiology:
Corynebacterium diphtheriae is spread via secretions of infected people or contaminated objects.
Cutaneous diphtheria occurs when a wound is colonized by the bacteria. As in any infection, prevention is diminished by poor personal hygiene as in indigent adults.
The respiratory airway pseudomembrane which often accompanies this disease is a result of destruction of the superficial layer of epithelium with fibrin, leukocytes, and debris.

signs and symptoms

signs and symptoms:
• initially mild sore throat
• dysphagia
• low-grade fever with increased heart rate
• rising polymorphonuclear leukocytosis

In children:
• nausea
• vomiting
• fever
• chills
• headache

The membrane is usually grey, tough, and fibrinous. It may be firmly adhered to the wall of the airway. The membrane may partially obstruct the airway making breathing difficult. It may become dislodged and cause complications such as complete obstruction.

Later:
• signs of toxemia, with increased WBC
• enlargement of cervical lymph glands
• in severe cases, the interstitial tissue of the neck may become engorged with exotoxin-borne edema that the person may appear "bull necked".

lab findings:
• culture on Loeffler's media
• (+) FTA staining
• albumin and casts in urine

course and prognosis

Incubation period is usually 1-4 days with a prodromal period of 12-24 hrs.
Conventional approach includes administration of antitoxin and admission to an intensive care unit. The antitoxin is derived from horses and adverse sensitivity is a concern. If the disease progresses, myocarditis may occur in the 10-14th day up until the 6th week. Heart failure may ensue. Neural complications include dysphagia from bulbar paralysis in the first week. Peripheral nerve palsies may be seen until the 6th week.

differential diagnosis

• strep throat
• laryngitis
• tonsillitis


footnotes